One Time Pad Key Distribution
This principle is commonplace, it is a key derivation from a shared secret. The academic thing to do is to use a Key Derivation Function or a MAC where hash of a concatenation is used, perhaps
$$\operatorname{HMAC-Hash}\;[\;\text{Key}=\text{(EC)DH Shared Secret},\,\text{Message}=\text{Counter}\;]$$

We call the output a derived key, and it can be a one-use key.

I would not call it a One Time Pad key, even if it is used only once to mask some payload with XOR, because the usual assumption is that a One Time Pad (key) is truly random, and this is only pseudo-random.