Fedgov is talking about taxing stock trades as well.
And NY/CA are talking about getting the IRS to collect for their states, by making it a Federal law allowing states to collect taxes from former citizens across state lines, and yes using the IRS to do so.
California already got spanked for charging taxes to former residents who moved...LATE 80’s ???
Taxation Without Representation was ruled for the former residents.
Same would apply in a future attempt, IMO.