Would that >= license be enforceable in court? It seems lame to create a license that forces you to agree to whatever future license changes come about.
It doesn't force anyone to agree with any changes.
It says "the recipient can use this under GPL v2 or any later version as published by the FSF", which means if they recipient is happy with the rights they got under GPL v2 they can keep using it under that version for as long as they like.
The only person agreeing to future license changes is the publisher of the code, and they're the ones that chose to publish it under "GPLv2+" or whatever.
It could go several ways but I can't see a judge wanting to entertain complaints that a new GPL version isn't to your liking if the changes are minor, especially so since it's always going to remain valid in GPLv3.
If the FSF goes rogue and changes the GPL to be incredibly restrictive (i.e., allowing proprietary redistribution, and I realise this can be considered permissive..) it might be possible to get it to be ruled invalid defaulting to the more permissive licence, especially if you have deep pockets, or if the FSF change the licence to be ridiculously permissive like 0BSD then it's not going to be legal in countries like Germany, either way any major change is likely to result in an international enforcement nightmare.
