Signed this few days a go.

Many games already do this and I would like to give honorary mention to NeocoreGames who have done this to their Van Helsing and most recently with Warhammer Inquisitor. Latter one just recently got offline support with all past seasons playable.

I dont think its unreasonable to require even live services or mmos to have robust end-of-life plan that quarantees customers that the game will remain playable in some form or another.