@pateb2 what you are seeing is expected, personalization is exactly that - we give the user the choice of how their data is shown, including the default view and any other additional views they want to add to that insight. 

For me, personally, I don't see the value in creating Insights in a Dev environment and Promoted these up - Explore Data / Insights is geared for self service, so we should be allow the business to produce the reports the need. As a former business user, having to wait and pay, for developers to create me a report I wanted, there is a huge value in business building their own reports. However, that said, you are where you are with your deployment model for Insights so a couple of things to consider:

1. The developed insight view, should still be there. Users who personalize the insight to should have additional options in the menu for the personalized insight, though its not always obvious. They may have changed their default view and not even known there was other options (common).
   1. 
2. If you are packaging certain insights in your PROD releases, then you could look at your CICD process to help identify when this issue might arise.
   1. You could further look to delete personalization instances of that Insight if there is a new version.
      1. Though I personally feel that would cause more friction than benefit
   2. You could look to publish in release notes to mention to the user base that a new version of this insight exists, they should have a look at the original (which may not be their default anymore)
3. You could go the nuclear route - delete the old insight, create a new one. Insights are easily copied via "save as", which will give it a new ID and all personalizations on the old ID will not be copied. Given its a data instance, your prod release would also have to delete it (as merge pipeline won't) and like 2.1 you could cause more user friction than benefits.

There's a chance I have misunderstood your issue, maybe the data is factually incorrect? In which case maybe options 2 or 3 would actually be a better solution. Will leave you to decide which is best.