Seriously if this continuity ends after SM it would be a shitty ending.

Team Rocket is still alive and kicking. No full battles in the final league. None of Ash's old Pokemon returning. None of Ash's old rivals came back. None of Ash's old friends came back except for Brock and Misty for a couple inconsequential episodes mid season. His final opponent is just his friend's brother who barely had a rivalry with.

The whole thing seems anti climatic.