Well thing is that it never had been standard and always had been very vendor dependent (for good reasons IMHO).
Don't get me wrong, I'm for EE to provide solutions adapted to today's need but innovation is by design not in EE (risk to fail is too high and therefore adoption would be too low as some child projects proved).
And today there is not a mainstream solution, some will use actors, others the plain old compensation pattern, other will stick to XA until perf become an issue etc...
So all EE can do is to enable these cases without being too much opiniated cause it would fail to cover main cases.
Standardizing is a very hard task and the best choices are often to not do in this area rather than doing wrong - it is how I see it.
Doing wrong makes the spec rejected and the platform bloated, postponing until there is a clear standard and added value doesn't bother anything.
EE can enhance the experience a lot in several area but don't think it is one (as data or nosql are not for ex).
Starting by embracing functional and reactive programming, being message passing friendly etc are area which can easily benefit from some investment.
Trying to normalize the state management in a distributed system is too solution dependent to become a promoted feature and providing interfaces you have to impl everytime is quite pointless so think it is where EE should assume to stop: enable all cases but don't force patterns.