To remove comments, one can also run, for example `latexpand --empty-comments --keep-includes --expand-bbl document.bbl document.tex > document-arxiv-v1.tex`. Latexpand should come pre-installed with texlive. Without the `--keep-includes` option, it also flattens the tex files into one.

But I'd consider removing comments by hand and leaving any comments that are potentially insightful.