I wish they would eliminate being able to execute .scr files which were used to share screensavers...back when anyone cared or windows even bothered to use them since its all lock screens. Now they are nothing but guaranteed malware and pretty common for that purpose.
There's absolutely no negative impact disabling the support other than someone still using Windows XP with custom screensavers saying "SEE MICROSOFT IS EVIL!!!"
PIF files are perhaps madder. They're configuration files for MS-DOS programmes running under Windows. But you can rename an .exe to .pif and it'll still work as an .exe as the same internal function to start an executable also handles PIF file parsing. But Windows Explorer considers PIF files "shortcuts", and so like .lnk files the file extension is always hidden even if visibility is requested.
This included 64 bit Windows (at least for 10), which can't actually run MS-DOS programmes, and has no real reason to actually try and do anything for PIF files anyway.
I was surprised to find screensaver support still in Windows. And they still have a bunch of screensavers like "3D Text" which appears to still be using the same code from its first release in 1998.
They also seem to have isolated them onto their own desktop, meaning that if a screensaver crashes then the users desktop won't be shown. That broke the official 'Bubbles' screensaver in Windows 11 - and they clearly don't test that stuff, because they released it anyway, broken.
There's absolutely no negative impact disabling the support other than someone still using Windows XP with custom screensavers saying "SEE MICROSOFT IS EVIL!!!"