https://www.bbc.com/news/world-us-canada-66124775 This seems like a poor and ambiguous way to sign a forward contract, though it worked at FTX for awhile.
Under the US contract law, an oral agreement is a valid legal agreement. Also mere marking "Yes" on an email reply confirms that the author of the email agreed to any proposal put forth in trailing mails. These do not require signatures. If we can assume that Canadian law is similar, then, I see no surprises in this court judgement.
Yes provided that merely answering "yes" via email is an accepted form of agreement to a particular contract. Not all agreements to contracts would accept "yes" via email as a valid legal agreement. For example real estate transactions would require formal signatures whether in person or in digital form via DocuSign is required, just an answer of "yes" via email is not enough. This case is very ambiguous and unusual. Usually an agreement to a formal futures contract that requires delivery of physical goods in such large quantity would specify agreement in a specific form and this is stipulated in the terms and conditions of the futures contract and a casual response just in a form of an emoji would not suffice. If this case is real, this judge is out to lunch and is completely clueless regarding financial contracts.