I think that only added another reason for them to do some changes with Jessie's team... she went like 200+ eps with the exact same team!Jessie goes 50+ episodes with no change
I think a lot of people speculated it... it usually happens with the TRio and I totally expect Jessie to "replace" Yanmega with a new bug next genwithout Dustox and gets Yanma/Yanmega.
Seviper will stay until there's a new poison snakeAnd to date, her other Pokemon remain unscaved.
Of course, they might never do another poison snake and it'll stay forever - but as I said I won't be surprised if they'll make one next gen especially for the anime
As time goes on the anime and games are more and more connected and the writers might ask them to make replacements for TRio Poké