Endorsement deals run out all the time.
I think if you really like something, you'd put your name to it till something better comes along, or someone offers you a better deal.
Ideally, but given you can still use whatever you like in the studio, and most of your time spent abroad will be with hired gear and not many hire companies have much out with the "standards" Twins, Bassmans, AC30s, AC15s, JCM800s, JCM2000s, Rectos and 5150s, then you're likely not using your endorsement gear outwith your own terrirtory anyway. So who cares if it changes all the time.
It's different if you've only a partial endorsement where you still have to buy gear. But in those cases, it's usually even harder to get your own gear abroad because the brand generally wont be arsed to try and help.
Plenty times I've been stuck hiring gear for bands who's endorsers wont supply with anything to use in the UK.