I believe this question continue the topic started here, linking for a completeness.
I tend to disagree. In my opinion the “release country / region” refers to the country/region in which the release was distributed by the original publisher / label (that is, the primary market). If a publisher located in France distributed release only in France, the release country is France. If a publisher located in France distributed release all over the Europe, the release country / region is Europe.
A huge hint on the intended distribution country / region are languages on the cover. If the CD cover is printed only in French, it is intended primarily for distribution in France. On the other hand, if the CD cover is printed, for example, simultaneously in French, English and German, it is intended not solely for the French market, but for other countries as well, hence “Europe” as the release country is more appropriate.
And a final criteria: if a MusicBrainz user bought the release on the primary market (that is, not a second-hand resell) in country ABC, than the release event was also in the country ABC.