So, by analogy, I go to buy a brand new chisel to do some woodwork, and the vendor says, "Oh, sorry, mate, you better not use that on wood that's more than 10 years old."
"Why?" I ask.
"Well," replies the vendor, "it's unreasonable to use this chisel on old wood."
Yes, it is. Excel on Windows and Excel on Mac run with different user interfaces, but the functionality is congruent without issue.
Where an issue arises, it is MacOS screwing up file permissions on a Windows server.
Microsoft would get sued by its corporate customers - via their business interruption insurers - were they to withdraw individual functions, such as =SUMIF(). Microsoft knows this, and so does Google (re Google Sheets). Hence why Google Sheets are fluent in both XLSX and ODS, and Microsoft was willing to extent support for Windows XP albeit for additional charges to the then userbase.
This is one reason why Microsoft is keen to move to the cloud using Office 365. To the extent that it can snoop on user data (or do so and get away with it), Microsoft would be in a position to count the instances of every function in use. And this is another very worrying possibility.
How so? Because Microsoft has form in screwing thing up based on "evidence". In Office, the move from the menu interface to the ribbon was a classic example of "evidence-based" research. Problem was, the "evidence" was flawed. The "evidence" was a survey of users. Power users were de facto excluded, because power users have jobs to do with no time to participate in stupid surveys. Microsoft pressed ahead anyway. On migration from Office 2003 to Office 2007, power users worldwide were comprehensively sabotaged when every keystroke needed re-learning. Even now, after all the re-learning has taken place, Microsoft has burdened its users with an even clumsier user interface, with more than double the number of keystrokes required to achieve anything, and loads of pointless, middling dialogue boxes, some of which have no useful business purpose, and no useful keyboard access at all (eg Excel's new "sort by..." functionality, an absolute time killer). So much for being a productivity suite: Microsoft has killed users' productivity! We now take longer to achieve what we used to achieve. How is that an advance?
But as most users worldwide use spreadsheets as nothing more than a glorious typing exercise, often without basic data management functionality within their spreadsheets, Microsoft is likely to find that its userbase in Cloud 365 use less than 1% of the functions in Excel, and start withdrawing them, to reduce the costs of supporting the "unused" functions. When that happens, and Microsoft's competitors stupidity follow Microsoft, corporate data systems will revert to a new Dark Age.
This is not a case of your cited issue, but rather an anti-competitive, emotionally-driven, emotion-causing, manipulative false error message that all software developers get up to. Yes, they drive me nuts too.
That is outside the scope of my project, which is to migrate from Windows/Excel to Linux/Calc (or, now, Linux/TBC). The reverse migration is down to somebody else!
However, I did discover a taste of the failures to come when I first used Calc as a direct replacement for Excel in the Linux Mint environment, blogged here (caution: some adjectives are not for the faint-hearted!).