This may now be a major impediment to connecting or boarding locally at YYZ. Given an option, you may prefer to connect and pre-clear US formalities via another gateway (albeit harder to do due to frequencies).

At YVR and YUL, for example, if you've checked bags elsewhere and connect to a US-bound flight, you don't need to wait for/retrieve your bags, you clear security and approach the US officials in pre-clearance without your checked bags at all.

Even if checking in locally at YUL or YVR, you will drop your bag before security too. US officials will get a screenshot of your bag and if they do want to inspect it manually they can call for it... all in all, this will be hugely faster for the great majority of travellers, at least for the coming week... who knows what the future holds for security in the short term thereafter.