He means whenever someone uses
@INovaeFlavien he'll receive a notification about that post. Could become spammy.
Personally I don't think that'll be much of an issue. I expect people will refer to people as IA, Keith, Jan, etc and only go to the (minor) effort of using the @FullUsername tag when they think it's warranted.
Newcomers who might think a tag is warranted when it's not are probably going to be unaware of who the devs are, and unaware of the @ tag feature anyway.