It'd be nice to think the parts you've highlighted are some kind of secret wink at the subject, but even mashing the contexts together like this, I'm not seeing it.
In the first quote, he's talking about development branches and testing things. He mentions server code because, most likely, they only have a handful of test servers running various branches of testing code. If a particular feature or function is coded on the client, it's (comparatively) easy for a developer to change some things, compile a version of the client with just those changes, and see what happens, without having an effect on anything anyone else is working on. If a feature is something that needs to be changed on the server, that change needs to go through more steps, and it's less likely any given developer can just whip something up and try it on the fly.
The part about the need for server improvements was specifically talking about the enormous clustercuss that was open beta/launch, and the scrambling they had to do just to get to the point where everyone could even log in and stay connected. That took so much time and resources that it screwed up their schedule. He's not saying anything about the current state of the servers, just that they were badly broken, and that pushed back all their other plans. And "additional system updates" is so laughably vague, I wouldn't take it to mean anything at all, especially given the way SE publishes & translates changes to their games ("Such and such has been adjusted" - Gee, thanks for the helpful patch notes, guyz). In that sentence, "system" just means "not UI," since he mentioned UI changes specifically, but didn't want it to sound like 2.1 was all UI updates.
I'm sure he is aware of the netcode issues. And I hope he does say something on the subject during the live letter (if not before; you never know!). And subordinate to that hope is the hope that anything he says isn't just more useless victim-blaming (research harder, WARs; zoom out). But I really don't think anything he's said in these posts has anything to do with it.