No to the DLC for Arceus. Given how well-received the SWSH DLC was, they'll want to get Arceus DLC right, and that game already involved a lot of work. Adding more to it will not happen quickly. We're getting Home compatibility, something Go-related(Hisui forms?), and a lot of back-patting over Arceus. Nothing else, in all probability.
The unlikely to be mentioned, but possible:
Some kind of QoL/bugfix/etc update to BDSP, possibly a similar one for Arceus, that's large enough to warrant mentioning alongside the Home update.
Remake/Sequel to some beloved Gamecube-era title. I expect this in a couple months, but right now they'll want to keep the focus on Arceus.
Clear mention of "Everyone loves some of the changes Arceus made to our traditional format, especially X, and we will be keeping that in mind for future titles". I don't expect to see this until the Gen 9 announcement, but maybe they'll want to build it up a bit.
(and I agree, 9 feels a long way off. Between the DLC and Arceus, they've had their hands full.)