It's the same chat as on the browser, so no separated systemsSo I'm not sure I completely understand.
Is this a Mobile Chat separate from PC Chat, meaning that Mobile players can't access the PC Chat, and PC players won't be able to access the Mobile Chat? If so that makes it much less useful since most guild leaders (of the guilds I'm in on live) are on PC, while most guild members are on Mobile. Kind of hard to disseminate information to the guild if there are two segregated systems.
I think the opposite. They need to make it available later on so there aren't more people joining just to spam globalIt isn't bad, from what I can see from the announcement. I'm a PC player though and will probably never experience it
However, as Inno I'd hesitate on making a chat feature contingent on researching an end-of-BA tech. For me, one of the main reasons I stayed in the game is because at the beginning of the people I met chatting while I was a new player. If I didn't have that feature, I'm not sure if I would have stayed, or at the very least stayed for a decent length of time... but that's just my opinion.