Hmm, this is interesting.
I need to dig up some people to do some more legwork on this, but I think we have to come up with something more conclusive if we want Markus' attention on this.
First of all, we're going to need to sim a bunch of 25+ year leagues to see if this pattern bears out, or if it was just your league. I'm not convinced there's anything to the relationship.
For example, I have one simple fictional league that I simmed out for 120+ years, starting in 2006, that I use when looking for long-term or historical reporting issues. Early on there were some dynasties, but it didn't level off.
In the first 25 years of the league:
SF appeared in 3 in a row, and won 2
Fort Worth appeared in 5 in 6 years, winning just once (hello Atlanta!)
Indy won 3 in a row
There were several others that won twice in a row or twice in three years.
But, leaping ahead:
- The Detroit Isotopes (

) won 3 straight from 2033-2035.
- The Fort Worth Hawkeyes appeared in 3 of 4 from 2037-2040, winning 2.
- The Atlanta Daredevils won 3 straight from 2048-2050.
- The Dallas Butterflies were unstoppable in the 2050s, appearing in 8 of 9 championships and winning SEVEN of them.

- The Irving Roadrunners were a force in the 2070s, missing the championship game just twice in the 11 years from 2068-2078, winning 7 of those!
Anyway, that was fun, but my point is, I think a lot more info is needed before I would call the connection relevant. In my year, I saw long spans of both dynasties and parity.
It may be a lot easier to prove simply that new hire managers all have default settings. But, I'm not sure that it ties to dynasties.