Personally I'd give Ukraine our 20 x 2A6Ms and 20 x 2A4Ms and keep our 42 x 2A4 training tanks while we determine what to replace our fleet with.
I wish there were actual production plans for the Abrams X. If we're going to upgrade we might as well get the latest technology since we know we'll hold on to them for decades. Abrams X is quite a bit lighter than the M1A2 SEP3, has a hybrid electric diesel engine and active protection system.
There's lots of negative press about German tanks at the moment, but realistically how likely is it that Canada will be looking at donating our tanks (of any origin) to another non-NATO country again? So our likely options for new tanks are M1A2 (for commonality with the US Army), Leopard 2A7 (for familiarity and commonality with many NATO nations) or the K2 Black Panther as an unlikely outlier (probably only would be considered if the industrial benefits/technology transfers offered by South Korea were too good to refuse).
Proposed tanks like the Abrams X, KF51 Panther or the ever shifting European future tank programs aren't really a good fit for Canada as we don't want to end up with another orphan fleet.