As a counterpoint, it would be quite unfair for the law to allow people to breach their agreements purely based on the medium used to enter into an otherwise valid contract.

E.g., what if the non-breaching person had invested considerable time or money complying with their end of the bargain in reliance on the promise? What if, as I understand the case was here, the parties completed multiple agreements over text and came to rely on that medium as the convention?

In any event, the analysis leaves a lot of room for a judge to consider the factual background and reach a fair outcome.