Existing HubSpot forms, workflows, and contact lists in your HubSpot portal are not affected by a website migration because they live in the CRM and Marketing Hub, not the CMS. The website migration only replaces the frontend pages and templates. Your forms, automation workflows, contact records, and lists remain intact in the same portal.
The nuance is in how forms connect to the new pages. When pages are rebuilt in HubSpot CMS, your existing forms need to be embedded on the new page templates. If the migration team creates new form modules instead of referencing your existing forms, you could end up with duplicate forms that do not feed the same workflows. Confirm with your migration partner that they are embedding your current form IDs on the new pages rather than creating new ones. Workflows continue to run uninterrupted because they are triggered by CRM properties and form submissions, not by the CMS layer. Contact lists based on form submissions, page views, or lifecycle stages keep functioning as long as the tracking code is properly installed on the new site. The one exception is enrollment history: if you are migrating from a different CRM into HubSpot (not just rebuilding the website), existing workflow enrollment history cannot be transferred due to API limitations.