We can confirm through numbers that the Yooka-Laylee is sold in NL, as it is found on markplaats.
On Ebay FR we can find the French version, which has the Attention on it:
https://ebay.fr/itm/154051816902Unfortunately, I do not have a source for aftermarket games in Belgium for a similar confirmation. Without a confirmation, the additional TLD of [BE] isn't put on the entry. We know [NL] is correct and we know [FR] is incorrect. This is why we will change [FR][NL] titles to [NL] and not [NL][BE].
If you can
confirm (or deduce through volume on their secondary market) these particular games were also sold at retail in Belgium, then you can add [BE][NL] to the titles.
In general, we would advise against adding a TLD to an item because one other similar item had it, or because of the presence of a language. If we don't know for sure, we don't want to potentially add wrong information into the database if we can help it. So this way, it is safer to have at least [NL] on these, especially if you do not want to do the research to figure out what is and isn't sold in Belgium.