I cant answer whether miners will disappear it would seem that some are trying to implement PoS algo to their chains but I like the PoS concept and ease of which it can produce good rewards without the expensive hardware required with PoS - i'm currently staking various coins and producing some handy rewards and over time these will amount to significant gains
That's the main reason why some POW platforms were migrating to the POS like ethereum caused by POS is much more conservative and the buyers will also get benefit from its token.
The token holders were deserving benefit from what they have bought with their money.
Miners will go away someday when bitcoin reached its maximum supply and there will be no more popular POW coin like bitcoin. The miners have no choice other than migrate into another POW coin.
This time POS is more popular compared with POW.