As long as they don't get rid of them all at the same time I don't think they'll see much, its kept variable enough with the different directors and the small cameo's so while there are a LOT of films with differing characters I think they'll pull it off, I think the problem that they'll have will come from the Disney merger, cancellation of the established Netflix characters and things being moved around for the pending arrival of streaming services will damage the "universe" more than characters being killed off..
That said its a huge money train and I'm sure they'll be profitable for a ling time yet...