There is currently no such status as "associate member" defined in the EU treates although the idea of special status for not being a complete member was floating around for a while now.
Just calling it a "unique alliance" or "deepening of their relationship" wouldn't have had such a public effect.
Half of the right wing influencers on X is going bananas because when the US was "offering" Canada to join them, they said a firm "NO" but for the EU they are opening the door.
Trump even said when the Canada joins the EU as associate member, it could be considered a hostile act.
All that for a status nobody knows yet what it will entail. More than a simple trade deal, for sure, but also a lot less than a proper membership.
[1] https://www.reddit.com/r/europe/comments/1qbq43v/european_in...
However, I could see a big argument for a labour mobility agreement similar to the NAFTA model, where EU citizens in a long list of professions have the right to work in Canada and vice-versa.
The reality is that the joining the EU as full members involves too great a sacrifice of sovereignty for middle powers like Canada, Australia, New Zealand, Japan, etc.. Brussels is too far away and the EU itself barely functions with the members it already has. There is, however, broad will among middle powers to work together more closely than they do now. This associate EU member thing needs to strike a balance where countries who join it can cooperate and contribute without feeling like the EU is becoming another U.S..
I mean, it's a very, very different type of offer.