It can but to my knowledge law enforcement in the US anyway have only done this once for a national security incident in the real world outside of a lab. If you have any links to this becoming common practice outside of a lab demo or security presentation on their own hardware I would be interested to save in my own documentation.

They can also buy cases that have anti-tampering controls that force a poweroff if the case is opened but that is getting into more costly edge cases. The hardware exists but is not datacenter operations friendly. It is also possible to force a wipe of ram on a clean shutdown but one must assume this won't be. As one example the feds took Mega's servers from Equinix after yanking out the cables and out the door they went.

[Edit] I should add for completeness sake there are kernel boot options to clear memory space before allocation and after de-allocation with a performance hit. Both are enabled by default on modern kernels now.

    init_on_alloc=1 init_on_free=1