It seems Nintendo Switch owners might be getting Assassin’s Creed here in the west. However it is unlikely to include Assassin’s Creed Odyssey.
Assassin’s Creed Odyssey which is available for cloud streaming in Japan only due to the infrastructure for streaming being available only there at this point of time.
An Assassin’s Creed Compilation has been listed by German / Dutch retailer Media Markt. Whether it is an actual thing remains to be seen, but it would be a nice get for the Nintendo Switch system. The listing noted a date of 29th March 2019 for €39.99. There is no information about what games this compilation contains, and at this point in time, Ubisoft has made no official announcement.
Unlike retailers that have a reputation for accuracy such as Amazon, we can’t be certain that the Assassin’s Creed Compilation listing is spot on. The original listing; https://www.mediamarkt.de/de/product/_acc-nintendo-switch-2504802.html has also been changed to ACC.