Very interesting question. Gergiev's no great loss IMO, I think he's been grossly over-rated for years. I have some of his recordings, none of them are essential
However, what about other Russian musicians? - there are many and some of them are well embedded in UK institutions:
Vasily Petrenko - former RLPO and now Royal Philharmonic chief - and critically acclaimed on many levels
Vladimir Jurowski - chief at the London Phil - and a great conductor IMO
Maxim Emelyanychev - chief at the Scottish Chamber Orchestra
I'd not want to be without their recordings..... but if any of them stood up and gave Putin their support or backed the invasion in any way I could change my mind about that.