Microsoft
MicrosoftCopilotTechWhiz nah, that would not be the case; as files within Teams are SP-sites, and when not included on the RSS list, they won't be searchable as stated in the OP: "Restricted SharePoint Search allows you to disable organization-wide search, and to restrict both Enterprise Search and Copilot experiences to a curated set of SharePoint sites of your choice."
But, there is a but, if some of those Teams SP-sites are part of the frequently visited SharePoint sites, than they are included as part of the max 2000 list, as paprud stated in her reply above.
The better (safer) solution would be an option where you can exclude certain data (while keeping it available in Enterprise search). The true problem statement is, organizations find GenAI/Copilot for M365 scary and perhaps too powerful to trust all their data with. So they want to exclude stuff from Copilot. RSS is a start, not a full answer, but the truth is organizations should really get cracking on decent Data Governance.
In short, using RSS will meet the goal where end-users don't discover information they have (accidentally) access too, just by continued interrogating Copilot, but there is no absolute blockage of certain (sensitive) data... unless you really have your Data Governance in order... which is bringing us back to square one.
