This is very unlikely to happen, but there’s precedent. The Bolivian president’s plane was diverted to Vienna, grounded, and searched because authorities believed Edward Snowden was aboard. There’s other examples of this shit happening (mostly in Europe).
The only thing far fetched about this scenario is that the US would employ this to randomly try to round up unspecified immigrants in order to detain them. If they catch wind of someone they deem high profile, though? Would not surprise me, but I would be surprised if they came after me because I shitpost on Lenny.
There are no standard flights that avoid US airspace when it would be faster to fly over. One, it’s a waste of time and money, and two, aircraft prefer to stick close to land in case they need to make an emergency landing (source: I vaguely remember reading that on Wikipedia once but I might have been drunk at the time).
If someone were legitimately concerned about this, they’d need to fly well away and back again (like make a flight change in Asia or Europe) so flight lanes don’t cross over the US.
Have the economy you voted for!