...yeah, more like they shouldn't be much of an excuse. But look at how many times we're still being given the answer "small dev team" or "hardware/server/infrastructure limitations" - basically just as much as in the first weeks/months after launch. (Re: housing, again, just to mention one example.) So yeah, I don't know how much common sense and logic apply here.
Also, regardless of what Yoshi said or didn't say - the fact that PS3 is gonna be dropped sometime in the future is pretty much given. The thing's close to its 9th birthday, which is a very long time in tech. And there's already a list of things they needed (and still need) to tweak because of the PS3. If FFXIV has a life of 10 or more years, we can pretty safely assume PS3 support will be dropped somewhere during that time. No need for Yoshi to comment on it in any way for that.