Welcome Todd!
I can't imagine why Keystone would drop those 2 lines -- Montana has been their best (full-sized) seller for
MANY years [as per advertising] -- not saying it *won't* happen, just that it would be a really big move IMHO.
The Avalanche & Alpine lines replaced the Challenger & Everest lines in 2010... but..... who knows!
Buying a Mountaineer (even if discontinued later) wouldn't be an issue... it would have the same warranty; plus,
the majority of parts & components aren't specific to that brand. Happy shopping!
Terri, the Chevy co-pilot