Canonical are apparently preparing for an IPO. If that happens, I’m pretty sure Microsoft will grab a good chunk of them and maybe absorb them completely later.
While Microsoft has been focusing more on the container side with Docker lately, they have also been cuddling with Ubuntu. Windows Subsystem for Linux (WSL), which runs Ubuntu in a cage, is only one of these examples. Observe also that e.g. Microsoft’s MS-SQL adapter for PHP only explicitly supports Ubuntu and RedHat, none of the other distros.
If the IPO does happen, see me back here in 2 – 5 years to resolve any bets 🙂