Selfhosting Matrix might be a solution if this passes. The surveillance is to be installed at the app level, imposed on the distributing companies (say, the Signal front-end), this is not a ban on. But if you're booting up your own application, it might at the very least be a legal grey area whether or not you need to implement chat control, so you could just not and the data will still be E2EE in travel for now. Easier than asking everyone you know to use GPG