Alot of the Xbox coaches use Facebook groups to communicate mainly, here is a link to Fabbl (the largest and in my opinion elite private league out there with many Competitions of all kinds) and a link to a Facebook group dedicated to the public leagues on Xbox.
@Thonidor, I was able to log in to the xbox bb2 and check things out around 12pm CST yesterday, there may be another update you need, try checking the updates in your "my games/apps" in the Xbox home screen/menu. But without knowing your exact situation it's hard to say why you weren't able to log in around the time of this post
It can be equally as frustrating being on the "conceded to" side of the situation, as they could only have time for 1 match as well but can't get the bb2 itch scratched because some opposing coaches can't handle bad dice and concede.
Not to mention in some cases coaches are likely to earn more spp than just the 5 they would get from a concede if the match were to play out.
I don't think the concessions limit was introduced into the champs ladder to benefit "hardcore coaches" or hinder "less tenured coaches" but to mitigate the number of conceded matches in the public leagues which had around a 50% concession rate (way too high, imho) before the champions ladder was added.
I believe conceded matches are frustrating on both ends. Less frustrating for the coach that gets the win but still frustrating.