Changes in aptitude promotion

I've been thinking about it lately and I conclude that when Pokemon evolves, their aptitude shouldn't increase unless you use some special item typically for increasing aptitude as it kills the importance of aptitude.

so here are the changes:

Tobi's Azumarill and Grotle were brought down to one making their aptitude being DeepRed and LightBlue respectively.

Trevor's Primeape was still in Green Aptitude like it was before evolving while his heracross remains the same.

Tan we're also the same as Trevor's case as his Beedrill's aptitude was brought down to LightGreen while his Ariados remains the same.

Dexter, also the same, his Persian was now DeepGreen like it was before evolving while his Pidgeotto remains the same.

Nathaniel, also the same, his Golduck was back to DeepRed while his Gyarados remains the same.

(you could read the changes back in chp.16)