The company is clearly focusing entirely on their SaaS version, which just makes sense in this day and age. They provide the stand-alone version for people who know about and want to continue using it, but obviously they don't want to drive any new users to this end-of-life product.

In my opinion, it's not a dark pattern, it's just softly winding down the old app. That's not an unreasonable thing to do. If you want a traditional app, there are other choices.