To clarify, although Canada does indeed have a division V available, it's very unlikely it will be needed for a long time. The reason it was created is because in the past other countries have had a problem arise where their lowest division filled up at some point during the season which prevented any new signups from those countries. So now in Canada and many other countries a precautionary measure was taken to avoid that problem by adding another division... just in case.
As I write this there are only 334 active teams in division IV. Div IV has the capacity to hold 1024 teams. So unless the amount of Canadian users triple from now until the end of the season division V will be vacant once again next season. There will be no division IV teams that relegate to division V.
It makes sense to do that. Although it does make it quite easy to advance a few more rounds in the National Tournament and possibly get that all important National Tournament game during the All-Star Weekend. Though the first few NT games are usually quite boring.
Don't get me wrong though, it's nice to get a few gimme games. Especially for those who have just started playing Buzzerbeater.