Yes I’d walk.
To wit. I am a lifetime gold member of a calorie tracking app; cronometer. I paid a large sum up front in its early days to have gold access forever. The business went subscription and now the gold membership is worth a lot on a yearly basis. They transitioned to a subscription model when the started to scale. Instead of booting me to a yearly subscription or limiting my features, they have honored the gold membership promise. This has been after many many years later and counting.
Another app where I paid upfront, Ulyssess, which said they’d have gold access forever if you paid upfront, went back on that promise a few months after taking my money and rolled me over into a yearly subscription. I ended my subscription and have been able to convince many people to not deal with the program because they do not honor their promises.
Look, fundamentally, a promise was made. Trust has been built and formed. A breach of that trust means I wouldn’t be able to trust the company in the future. I wouldn’t trust someone who went back on their word for similar reasons. It is simple.
I would suggest that if they really want to develop additional new things that expand beyond what the app had originally intended…they go get external funding, develop new business lines (i.e. streaming a live workout / q.a. session over twitch) or monetize existing free services (i.e. podcast) for increased cashflow, or even undertake the development of a tri-focused separate app as many of the ambitious project ideas fall under that. There are options outside of hosing subscribers who have supported the company for many many years by going back on a promise made in the early days.