So this just popped up. It’s been reported that Amazon.com now lists a double pack of Sonic Mania (the vanilla version it appears) and Team Sonic Racing for Switch. There aren’t any listings of the pack for other platforms yet upon checking. Also it’s not clear if this is yet another of those “put two boxes in a cardboard sleeve” type of releases that Sega do occasionally, as opposed to cramming both games into one cartridge/disc.
Amazon currently lists the pack for an October 26th, 2020 release in NA. If any new information pops up for the pack, we’ll let you know.