I did my thesis using corporate data (I used to work there, they don't give their information freely or sell it), data is from 2009 to 2018.
I collect the data, analyze it, everything normal. However, after my thesis was approved and submitted, I saw that the company has modified some of their data from 2009 to 2018, historical data from the past was changed (they have valid reasons) but I am worried that if someone tries to verify the source of my information, they will find different data and think that I commit fraud or data manipulation.
My supervisor and many people told me that nothing wrong will happen because my research was in a specified period of time when data was presented like that, they also told me that after a thesis approval, no one verifies data source. They also told me that the verification of data source is done before thesis approval.
However I am still worried, because it is not common for a company to modify data from the past.
My thesis wont be published because the used data is privated, so they are allowing me to not publish it.
Any ideas of what should I do?