Canada has a privileged relationship now with the Pacific Alliance members because of our web of FTAs and the extent to which we're in their markets already—and they're in ours, to be frank—and because of the richness of our bilateral relations with each of those member countries.
There would be a technical answer to your question once the Pacific Alliance is more advanced and we know what harmonization would be happening beyond our FTAs. That's a technical question that can't be answered until the Pacific Alliance is more advanced.
On the broader foreign policy level, right now we have that privileged relationship with Pacific Alliance countries. In the hypothetical situation where other countries outside our hemisphere are joining the Pacific Alliance and we're not, can I see them surpassing that privileged relationship we have with the Pacific Alliance member countries? It's possible, but that's on a broader foreign policy plane.
As I said, there's a technical answer to your question that can't be answered yet. Would we be missing something by not becoming full members? Quite feasibly, but we don't know yet what that might be, because it depends on how they surpass what we have in our FTAs.