Yes, several.
1. The only two actual written rules we have for posting in the Deals forum are "no self-promo" and "affiliate links disclosed and confined to a marked thread".
Everything else is up to the preference and discretion of the poster (subject to intervention by the mods if found inappropriate, of course).
2. Maybe it's just a personal thing, but if I were following a dedicated thread for notices, I wouldn't care to scroll past umpty pages of rambling and increasingly off-topic text for an offer I wasn't interested in.
3. This particular offer is very, very limited in being only available to one country that I've been able to find, so marking it upfront as being available for Canadians only with the "CA" in the title helps to draw people's attention to it if they happen to be Canadian, while warning non-Canadians off it so that they can avoid too much disappointment (and scrolling), without taking up too much visual space, comparatively, IMHO.
4.
This.
Hope this answers things for you.