"Officials said an initial surge was from influenza but the number of kids sick with respiratory syncytial virus (RSV) is unusually high and still increasing."

Unusually high?

The data and I beg to differ.

It took me 5 minutes of fact checking using published data the work the journalist should have done.

source: https://www.canada.ca/en/public-health/services/surveillance/respiratory-virus-detections-canada/2021-2022.html

https://edmonton.ctvnews.ca/mandatory-ot-staff-vacation-cancellations-possible-as-stollery-sees-rush-of-sick-kids-1.6202645

Respiratory Virus Detections/Isolations in Canada 2021 – 2022 - Canada.ca

Respiratory Virus Detection Surveillance System data from Canadian laboratories on the number of tests, and positive tests, for influenza and other respiratory viruses.

So if the numbers are high (total kids sick in hospital) - there may be something else going on - and it is not unseasonably high RSV. It may be more severe RSV.
@dgbassani Or same RSV but weaker immune systems, which could be due to covid?