Is this the future for Class A's?

Don't forget that when it comes to government regulations that affect big rigs and their engines, the RV market is not a concern to anyone. No one asked the RV industry how they felt about DEF. The Prevost type coaches will still be around because the regulations will probably affect buses and they are still built on a modified bus chassis.
The gas coaches will remain as long as the engine manufacturers can make money in markets other than RV's.
In my opinion, Tesla will not try to work out any deal with CG's. Their focus will be on the much larger commercial market.