let me know when I can get a native build of Office for Linux
Meanwhile Google wouldn't need to provide support for Chrome on Windows ARM(or any other platform) since it's not a commercial product consumers pay money for and are entitled to support, it's just a free product shipped withotu warranty financed by vacuuming your personal data.
The parents argument is that Linux's user base is smaller because critical applications like office are not available there.
These arguments are not mutually exclusive. Microsoft would rather keep it's dominate windows market share _and_ have less support burden.
On the other hand, Steam making Linux work well is a massive support burden for a smaller user base, but it prevented os vendor lock in for their platform.
Decisions to release or not release software is not so easily distilled to single metrics such as support burden.
Bigger than the Windows on ARM market share, that's for sure.
Most them seem quite happy to use Google Docs, so Microsoft Office 365 should also be alright.