This https://puri.sm/posts/tpm-by-default-and-free-international-... says they are moving to including the TPM in all systems, but there are some UK models left in stock without it.
The TPM is a security feature--you don't have to use it. I have not used it on my laptop but I see from the documentation that it is different from some other trusted computing systems in that the end user controls the keys and what is loadable, not the vendor.
As the QubeOS folks will tell you, TPM is necessary for Anti Evil Maid.
For a company whose advertising copy on their "Why Purism?" page includes, "We believe people should have secure devices that protect them rather than exploit them,"[2] only allowing removal of the TPM chip for a particular keyboard layout is a pretty big red flag.
[1]: https://puri.sm/shop/librem-13/
[2]: https://puri.sm/why-purism/