Just after the MLB lockout ended last March, news leaked that the Cubs and Cardinals would play in London sometime in 2023, as part of MLB’s plan to play games there (and in Paris!) over the next few years:
With MLB returning to London, #Cardinals are in line to host the #Cubs there in 2023, pending a finalized schedule, according to a source. Team is hopeful. It's obviously early with CBA fresh.
The two-game series between the rivals set for 2020 was canceled due to the pandemic.