Not true, the instruction set of eBPF itself /is/ Turing complete. Linux is one implementation of it and the verifier currently imposes restrictions in order to not destabilize the kernel (e.g. infinite loops). But that doesn't mean it's not not Turing complete. E.g. in future there could potentially also be a mode that allows to run unverified eBPF programs. Think of it like kernel modules which are also not verified for safety, but can be loaded with the right permissions like CAP_SYS_MODULE. In future I can image a similar mode/option for eBPF as well as long as the user has the right permissions to do so.