Re: Windows Server 2008 (R2) was supported on Itanium until 2020.
"it was enough to keep Itanium support in Linux for a decade or more after Microsoft had given up"
"I’m not talking about continuing to sell the product, I’m talking about continuing to offer updates for it."
I'm not talking about sales either.
Microsoft dropped Itanium support in 2020. Until then MS offered updates for the Itanium version of Windows 2008. Linux kernel dropped Itanium with 6.7 - kernel 6.6 will be EOL in 2026.
The difference (2020-2027) in support is less than decade, so how did you come up with the 'decade or more after Microsoft had given up' quote?
Itanium failed miserably and both Linux and Windows could have dropped support even earlier for all I care...