Ultimately this isn't going to matter much as Tekken is well established now and we are at the tail end of the console generation and FG era anyway.I'm talking about the actual repercussions of this decision for actual tekken players, not twitter/forum whiners.
Does Bamco look greedy? Hell yeah. Does it matter to a tekken player? No.
In reality, they have to justify the development of any new kind of content two years after launch and since this sp had less characters, this is probably just a way to increase the perceived value of the sp. I just find it weird they've chosen this specific thing to paywall over the others, because this is exactly how you get bad PR while offering an amazing improvement to the game.
This is just a bad precedence to set in the future must like the huge amount of MTXes in certain FGs already. Now every company is going to look towards nickle and diming basic features like frame data display. This is how it starts. Remember when all the custom item options were available in a SC game? Now they are sold out piecemeal as DLC. Same for stages, fighters, cosmetics and features even story mode elements.