Got an answer after emailing the app providers. Bottom line is if Tesla does not approve the app then it will not work so basically any app that needs updating will eventually fail. This is bad news as there are a few out there like Stats which is quite popular.
Here is the response I got.
Tesla recently made a change to their login system that requires us to update the app. Normally, that wouldn't be a problem, however Apple recently made a policy change preventing apps from using unofficial APIs from Tesla. Ultimately, this means we are not allowed to update the app, and therefore have no way to make it work again until either Tesla makes their API official, or Apple changes their approach on approving updates. We're extremely frustrated and disappointed, and monitor the situation daily to look for potential options. We've removed the app from sale in the mean time, and keep pushing to do everything we can to get it back and working.