Overview of the update
The Microsoft YouTube demo presented on July 29, 2025, explained upcoming changes to SharePoint Online that affect classic publishing sites. In particular, the video clarified how new restrictions on custom scripting and site creation will change administrator workflows. As a result, organizations should review their SharePoint inventories and prepare modernization plans well before the rollout window.
Moreover, the presenter from Microsoft highlighted a phased approach to enforcement, offering a short-term path for those who need more time to adapt. Consequently, stakeholders have an opportunity to balance urgent migration needs with long-term modernization goals. Therefore, reading the announcement carefully and mapping affected sites will reduce surprises later.
What Microsoft announced in the demo
First, Microsoft stated that creation of new classic publishing sites and activation of classic publishing features will be blocked unless a tenant-level switch permits them. Second, the demo outlined changes to the no script settings that will restrict custom scripting on templates tied to publishing sites. Also, a new capability will allow property bag updates at the site level regardless of the no script status, which gives administrators a targeted control mechanism.
Microsoft communicated these intentions through its Message Center and reiterated the timeline: mid-September 2025 for the initial rollout and a temporary enforcement option that can be extended until March 15, 2026. Therefore, administrators can use PowerShell controls as a limited workaround while they plan modernization. However, the company stressed that long-term reliance on classic publishing will not be supported.
Impact on migration projects and planning
The change shifts many migration projects from simple lift-and-shift to a deeper modernization effort, because classic pages and web parts often require transformation to work properly in the modern experience. Consequently, teams must allocate time for page transformation, refactoring incompatible web parts, and manual review of customizations. For example, heavily customized publishing sites may need both automated conversion tools and human editing to preserve critical layout and content.
Additionally, timelines and budgets can expand when modernization is included in migration scope, so project managers should account for this sooner rather than later. Meanwhile, organizations that delay action risk having to use temporary PowerShell exceptions, which can introduce governance complexity. Thus, combining automated tooling with phased manual remediation helps control cost and reduce disruption.
Tradeoffs and technical challenges
On one hand, disabling pervasive custom scripting improves security and governance, reducing the attack surface and preventing unsupported customizations. On the other hand, the move removes flexibility that many organizations relied on for tailored experiences, which forces extra development or redesign work. Therefore, teams face a tradeoff between tighter security and the short-term cost to reimplement or replace custom functionality.
Moreover, converting complex publishing sites can reveal legacy dependencies that tools cannot automatically fix, including custom code, third-party web parts, and specialized branding. Consequently, administrators must plan for manual interventions, user acceptance testing, and possible rollback strategies during migration. In practice, balancing speed, cost, and fidelity requires careful prioritization of which sites to modernize first.
Practical steps and recommendations
First, inventory all classic publishing sites and rank them by business impact, customization level, and usage. Next, assess which pages and features can be automated using Microsoft’s page transformation tooling and which will need manual rework. By doing this, teams can sequence work to deliver the highest value conversions early and reduce overall risk.
Additionally, communicate the timeline and available temporary exceptions to site owners and stakeholders, and avoid treating the PowerShell workaround as a permanent solution. Finally, invest in training for content authors on the modern experience, test transformed pages with end users, and establish governance around custom script and property bag usage to prevent future drift.
Conclusion and next moves
The YouTube demo from Microsoft clarifies that the platform will increasingly favor the modern SharePoint experience, and that classic publishing site creation will face new limits starting in mid-September 2025. While existing sites will continue to work for now, the announced restrictions create a clear deadline for modernization planning. Therefore, organizations should act now to avoid rushed migrations and to protect security and user experience.
In closing, balancing the security benefits of stricter controls with the practical costs of modernization will require cross-team coordination, realistic timelines, and staged remediation. Consequently, thoughtful prioritization, use of automation where possible, and clear communication will help organizations move to modern SharePoint with minimal disruption.
