TLG has become more about what it means to Sony than what it is. The jokes about its death play into a narrative about Sony's inability to deliver on a timely fashion, the state of Japanese development, etc. The constant interviews checking in on its existence with no sign of the game, it's like the industry's version of Castro.
When it's actually shown, none of that is going to be a factor, unless it's being made in the West anyway. The game itself isn't a big deal. The day after its announcement there'll be a few threads 'Ten years for that?', 'Not even Ueda's game at this point', 'TLG is dead, LOL' or whatever.
People frequently mention the concept that games (or anything really), can't live up to the hype of prolonged development. And while I disagree with that notion, TLG is an interesting example, because I don't think the hype ever really existed based on what the game actually was to begin with.
Ultimately, we will see. I don't believe it will be a big deal, no.