Text:
I consent to Plex to: (i) sell certain personal information (hashed emails, advertising identifiers) to third-parties for advertising and marketing purposes; and (ii) store and/or access certain personal information (advertising identifiers, IP address, content being watched) on my device(s) and share that information with Plex’s advertising partners. This data is used to deliver personalised ads and content, ad and content measurement, audience insights and product development. Your consent applies to all devices on which you have Plex installed. You can withdraw your consent at any time in Account Settings or using this page.
Soure: https://www.plex.tv/vendors/ (Might have to clear cache)
Can also read about the changes here: https://www.plex.tv/about/privacy-legal/
Can I guarantee? There are no guarantees in self hosting. By this logic you can never move away from Plex. There's always unknowns. There's always new issues to trip over. Plex is hardly without it's own warts, but because they're 'known' to you and your users nothing else will ever be able to measure up.
It's a logical fallacy and a trap.
I set up Jellyfin basically overnight when the Plex pass changes occurred. Reverse proxies are trivial, as are docker containers, don't let the anecdotes about things being hard or VPN being needed intimidate you.
There were absolutely bumps in the road. I had to make users for each person and email them customized sign-up links. Yes, that kinda sucked, but that's the price for running and controlling the authentication yourself instead of though a 3rd party service that can and absolutely will eventually use that data to snoop.
Most of the time, once sent the link the users were fine, 9/10 of my users had no further issues and quickly adapted. For the last 1/10, I had to trouble shoot a few things and eventually ended up recommending a different device to connect with (it was an old TV with a really old version of Plex for TVs, they ended up buying a $40 Google TV device from Walmart and got set up that way).
The whole time I was running both Plex and Jellyfin so the migration process could happen at my speed.
My point is this: no, it wasn't painless to switch. Yes, some tech support was required. Yes, the user who was getting hundreds of dollars (annually) of streaming services effectively for free had to shell out a paltry sum to upgrade and actually enjoys their experience much more now. No, that didn't make it impossible or not worth doing.
I'm not saying what's best for you and your users, and I'm absolutely not guaranteeing you'll have no issues beyond these, but I hope you understand your hands aren't actually tied, you're just boxing yourself in.