I see absolutely no reason to assume company culture is unlikely to change much over 10-15 years.

This does not match with reality. When a company is on the chopping block there are many instances of them finding a way to make things works. (eg. Big three after the bailouts, Ford running up the launch of the Taurus, Kia in the 70s, Nissan when Carlos Gohsn joined etc)

0 reason?

Company culture changes all day, every day, in reaction to thousands of factors, any one of which could prove to be significant.

It seems absurd to me to expect company culture not to change much over 10-15 years.

I think Toyota and their "5 whys" and Tesla with their "move fast and breaks things" are decent examples of ways a culture has lasted over time and has continually effected their products.