Assuming these games DO exist and DO come out by the end of the year...

We don't have that many Nintendo compilations to compare a Mario Collection with. That said, Kirby's Dream Collection on the Wii sold 0.69 million copies, about 40% as well as the previous year's Kirby title, Return to Dream Land, while Metroid Prime Trilogy sold 43% as well as Metroid Prime 3 did a few years earlier. So I think it's perfectly reasonable to expect a 3D Mario Collection to sell somewhere in the 30% to 50% of Odyssey range over its lifetime. That would equal 5 to 9 million copies lifetime, not exactly a bad total.

As for 3D World Deluxe, the best comparison would be with other Wii U titles on Switch. Some games like Mario Kart 8 sold way better on Switch than the Wii U, and even smaller games like New Super Mario Bros U, Donkey Kong Country: Tropical Freeze, Pokken, etc. Only the rare oddball like Captain Toad and Hyrule Warriors doesn't exceed Wii U sales, and even those were in part due to competition from the 3DS versions. So it's generally reasonable to expect 3D World Deluxe to sell in line with what it sold on the Wii U, 5 to 6 million copies.

Combined, that would be 10 to 15 million copies between the compilation and the port, assuming of course that the release of two 3D Mario titles doesn't cannibalize sales. Regardless, that WOULD be enough to push sales, but NOT on par with the big hits of 2017, 2018, and 2019.

Love and tolerate.