Are Typhoon class submarines extinct

Nope - one is still commissioned and active with the Russian Navy fleet (TK-208 Dmitriy Donskoy). Two others remain in commission, but are in the Reserve fleet and not active (TK-17 Arkhangelsk and the TK-20Severstal). The other 4 vessels of the 7 Typhoon-class have been scrapped.

The Russians have stated that they will keep them open for future modernization or conversion to SSGN's (Cruise Missile Submarines).