Hm, I would predict that BW is not going to limit themselves to that extent. That said, limited FTL comms would be kinda cool. To a very small extent, this was still the case in ME1, where comm buoys had limited bandwidth (this was never an issue for Shepard though, since he was a spectre). But remember that salarian who called his brother from Novaria because he couldn't access information on Anoleis otherwise? Little tidbits on the side like this would be cool even if we are not affected ourselves by it.
Depending on how far advanced ME:A Tech will be when compared to ME3 Tech, I could imagine two scenarios:
1. The tech is not much more advanced and they only have FTL com lines to 1 or 2 fixed locations via QEC
2. We are building our own comm buoy network as we explore
In the end, I doubt it'll make much of a difference though. We will be able to call whoever we have to call whenever we have to call when the plot demands it. I am sure of that.
That said, it would be good if Admiral Hackett wouldn't call us EVERY single time we enter a new system. 