Update: Well, that didn't go exactly as planned. The Yakuza Remastered Collection has been officially announced, but it's not really a collection -- at least not yet. Yakuza 3, Yakuza 4, and Yakuza 5 are all coming West, but they're being released separately. The bright side is that Yakuza 3 is supposed to be out later today on the PlayStation Store.
And yes, if you buy The Yakuza Remastered Collection (it's £49.99/$59.99) on the PlayStation Store, you get all three games -- just not right away.
Yakuza 4 will be released on the 29th October, and Yakuza 5 will launch in February 2020. All three games are remastered at 1080p, and will run at 60 frames per second.
SEGA says that a physical edition of the complete Yakuza Remastered Collection will be made available when Yakuza 5 Remastered hits in February 2020. Apparently, SEGA is even considering bundling every Yakuza game into one package at some point, although there are no further details on that.
Original story: Great news for Yakuza fans: it's looking like SEGA is about to announce something called Yakuza Remastered Collection. We assume that it'll include the PlayStation 4 remasters of Yakuza 3, Yakuza 4, and Yakuza 5. The collection has been outed on the US PlayStation Store, which currently lists it as an upcoming release.
Hopefully this all turns out to be accurate, because we'd much rather get all three Yakuza titles bundled into one collection, rather than having to wait for each game to be released separately.
We'll update this article as soon as SEGA makes an official announcement.