I don't really understand the hypothetical problems here. "The copyright office head would be a presidential appointee, which could make the copyright office more political". I mean, I guess? Are people worried they're going to start selectively enforcing copyright law? But they don't enforce copyright law right now...
Odd that the article doesn't mention parties at all, although perhaps this was in an attempt to avoid accusations of partisanship that might ensue from stating facts.
Anyway, a quick look at https://www.congress.gov/bill/119th-congress/house-bill/6028... indicates that all 4 sponsors of the bill are Republicans. The Actions tab seems to indicated that the bill got only 12 minutes of debate before being passed,; I hope this is an artifact of how the page is updated rather than the actual time spent on considering it.