[Acey]

Edit: you posted that as I was typing ^^... there are errors in that transcription which is not surprising given the speed he gets it out

Listening to the ATC. Toronto always does this these days, but one tower controller works runway 5/23 and 6L/24R at the same time, which is crazy to me. They must get do a lot of spinning in their chairs up there. Doesn't appear to be a factor... these guys are amazing.

There is no specific mention of shear but the weather report 12 min before the accident said wind 270 at 28 gusting 35 with blowing snow... that's nasty. An American Embraer, roughly the same size as the accident plane, landed a couple minutes prior and didn't say anything about poor braking, gusts or shear.

Plane: Toronto Tower, Endeavor 4819, OMTOK ILS 23
Tower: Endeavor 4819, Toronto Tower, wind 270 at 23 gust 33 clear to land runway 23, you might get a slight bump in the glidepath there'll be an aircraft in front of it
Plane: Clear to land 23, Endeavor 4819
(unrelated comms)
Tower: Wind check 260 at 24 gust 33
(unrelated comms)
*accident airplane crosses landing threshold*
Tower: Echo mike tango medevac line up runway 23, it'll just be once you cross the runway
EMT Medevac: *mic click to acknowledge*
*accident plane cartwheels*
Rouge 7105: Rouge 7105 OMTOK final 23
Tower: *panic voice* Rouge 7105 pull up and go around
Unknown: this airplane just crashed on 23
Tower: Rouge 7105 pull up and go around
Tower: Mike tango medevac you can just stay there
EMT Medevac: we'll hold here, echo mike tango medevac
Tower: Rouge 7105 stop climb 3,000

tl;dr:
- ATC did great and provided an additional wind check prior to touchdown
- no reports of shear from previous arrivals
- the crosswind component appears to be within the legal limit. Based on tower's wind check a few seconds before touchdown, the 33 knot gust from 260° is ~17 knots of cross. A quick search suggests, on a slippery runway, a limit of 22 knots for the CRJ-900