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
https://www.kucoin.com/news/flash/bitcoin-bip-444-soft-fork-proposal-sparks-legal-and-moral-debate