There are some errors in the article. May two four is a distinctly Eastern Canada slang. In western Canada, it is simply May long weekend.

Two four to refer to 24 beer is also Eastern Canada. In western Canada, you call it a flat.

Finally, as a Canadian who has lived outside of Canada for a long time, Canadians really do use eh a lot. It is just that it is a subconscious element of the language that we are not aware of. For the record, Americans use huh a lot in similar contexts and I'll bet they are similarly unaware.