In my opinion, I don’t believe there would be a consequence in posting your lecture materials to YouTube for class viewing except for a clear way for you to retain your intellectual property by making videos private or deleting them after date X.
In fact, I would argue that with YouTube you retain your intellectual property rights more so than if you post the content on Brightspace. At present, the question of intellectual property for distance education is very much unsettled for our members. There is no stated firm position or direction from the employer, save for the acknowledgement that there is a problem created by the distance education shift. Since there is no letter of understanding about intellectual property in the context of COVID, it is logically possible that any content posted to Brightspace could be re-used again in the future without paying you more money for it.
For more info on the IP rights in our collective agreement, check out article 10.14 here: https://aptpuo.ca/wp-content/uploads/2019/11/fullagreement2018-2021-to-be-signed.pdf
You are not required to format your distance education course in any specific way or using any specific platform. Part-time professors have the academic freedom to decide what content delivery method works best for them.
Caveat: I am not a lawyer, so all of the above is essentially my humble opinion. For a more informed opinion, you may want to write to jsdaoust(a)aptpuo.ca
If anyone else wants to chime in / has more info to add, please join the convo!