What is wrong with just using forum...? All the patch notes are here, even from those old times... Eg. 'guilds will be introduced soon'...
Current can be read in-game..
Most notes wouldn't fit in in-game mail message btw, the mails have such low charlimit... (or maybe I just type too much...)
But yea, devs, drop gw2 and bugs and introduce spam to our inboxes! Yay!
(well, mouse, your idea is kinda ok, but unneeded and hard to implement..)