Those year line comments were entered on the French page. Only the English page pulls in the French comments if the English comments are blank. None of the other languages do that. All pages are like that. Probably because it gets very messy if several of the other languages have comments. You could end up with the English page having French, Spanish and Russian comments. It wasn't a problem when only had English and French. If English was blank and French wasn't use the French comment. If French page was blank use the English comment. So my guess is it's not a bug but the design intent with all the new languages.
By the way, all 3 of your links you posted are identical.
There are only two languages you can edit the catalog in; French and English. The other languages have no data (this includes year line comments) they could share and are pulling data for translations for not-shared fields of the catalog page versions from, I believe first English, then if that has nothing French.