If you check research related to this and the DEFCON talk where somebody actually put thermite into the drive, there won't be a puddle of molten metal.

You can put thermite on it once you burned the parts if you want.

The DEFCON guy used 15 grams of thermite. An AN-M14 TH3 incendiary grenade contains ~750 grams of thermite (technically thermate). Those are two different things. Entirely.

Here's what 1 kg of thermite does to a hard drive:

https://www.youtube.com/watch?v=3lnqeodIIUw

I'm comfortable that the Curie temperature has been exceeded for all of those platters. :-)

Good luck getting that into a datacenter.