To be fair, Sega has never wanted to make Shenmue 3. Ever, apparently. Otherwise they would have pursued it at some point in the past fourteen years. To Sega, Shenmue was an IP that was going nowhere fast, and they were more than happy to dump it and proceed with making many Sonic games that continue to make us cry tears of agony, most notably since Sonic '06 when the series completely jumped the bug ridden shark and has sort of almost recovered.....sort of. Not really.
Anyways, Sega has been in no position to make a game that could be a total flop. Some older third party devs aren't doing amazingly at this point, and I'm sure Sega is just following the money to avoid completely falling into the financial shitter from too many flops. If that means making Sonic Boom games that sell like crap with gamers but great with fans of the questionable TV show, they'll do that until the profits dry up. Sega doesn't want to end up in a ridiculously perilous Capcom level position if they don't have to.
As for Shenmue 3, the creator knew exactly what he was doing at the Sony press conference. He came to Sony before the press conference and knew what Sony was giving to the project: marketing and a PS4 port depending. If anything, he intentionally picked the time to present and got Sony to agree to it for maximum exposure, though it also ran the predictable risk of people assuming Sony was funding the project. It was something Shenmue's creator should have pointed out right then and there, not left to find out later and then hitting basically a full financial stop once the news spread far enough about the project's true funding source. None of this was on Sony because quite frankly, they did a stellar job presenting in a way that garnered a mix of sympathy and nostalgia.
But yeah, Sega don't care. They just said "use our IP and pay us x% of all sales" and Shenmue creator dude said "okay".
