Hmm, I wonder why they decided not to include Legends this year? Was it just to hard to try to work all four shows into the crossover?
They made it work logistically last year, so if they wanted to I'm sure they could have done it again, but then another threat that requires twentyish heroes to deal with it would have been a bit repetitive so maybe they're trying something different. And dropping Legends makes sense because there's a lot of characters there, and it has fewer episodes than the rest of the shows, so a crossover "stealing" one of those is more noticeable.
As much as I like seeing the various team members interact who don't usually get do so, I wouldn't mind if this season it's just the big three and Batwoman.