Santiago,
I don't have the exact URL here but if you check the thread you'll find it.
There are at least 3 historical committers including the likes of Arjan who may simply have a lot on his plate, not sure if he stopped for another reason.
You or your or predecessor should know the case where at least one former EG member from Red Hat at the time resigned over a dispute or something.
Not everyone including Markus was in the EG of JSR 311 in 2008/9, but I was both in the EE platform JSR and EC at the time, so all the versions went by me in more than one role including approval by the EC.
MVC has a couple of issues, also regarding its possible inclusion in Jakarta EE. I heard several first hand by its Spec Lead Ivar who did not exaggerate kindly calling me "The JCP guy" yesterday at CodeOne ;-)
I helped the former Config JSR out of its gridlock together with the Spec Committee and other bodies like the EC. As MVC is a little more progressed at the JCP, it seems a bit more complicated, but for Jakarta EE 9 or 10 there should be hope for it.
The duplicate spec at Microprofile for Rest Client was seemingly overlooked, but maybe as project lead you know best, if it would be good to contribute those things back to Jakarta Rest or they do something not worth standardizing.
I used and helped several MP specs especially Metrics or Health, but I did not have any hands on need for the Rest Client.
Werner