It wouldn't be out of character for Luke to propose those but if so, why wouldn't he just use his own name. I don't see any attribution to Luke in BIP 444 but maybe I'm just missing it. Here's a link to the article that says he denies being the author

Bitcoin BIP-444 Soft Fork Proposal Sparks Legal and Moral Debate | KuCoin

In accordance with Cryptonews, a new Bitcoin Improvement Proposal (BIP-444) has sparked controversy within the Bitcoin community. The proposal, pub...