I'm wondering what they'll do to replace it. You can still buy the IQS550 chip it's based on and apparently make a very similar PCB. [4] The black frosted glass seems like more of a challenge for most DIY keyboard makers, maybe not for MNT. The replacement project I saw recommended "2mm thick matte acrylic".
[edit: or maybe the TPS65 manufacturing restarted? mouser apparently has it in stock. [5] although that's the A unit without the surface.]
[1] https://shop.mntre.com/products/mnt-reform-capacitive-trackp...
[2] https://www.digikey.com/en/products/detail/azoteq-pty-ltd/TP...
[3] https://mm.digikey.com/Volume0/opasdata/d220001/medias/docus...
[4] https://github.com/geek-rabb1t/GR-Trackpad65
[5] https://www.mouser.com/ProductDetail/Azoteq/TPS65-201A-S?qs=...