What Are Pokédex Current Recommendations Based Off?

After completing the Galar Region Pokédex and the Isle of Armor Pokédex there is a new display that shows Current Recommendations:

What are these current recommendations based off of?

The recommended regions seem random and they change. The Pokémon could just be weather related?

Solution 1:

After completing the dex you will receive a different set of current recommendations.

These current recommendations are based off of which Pokémon have a higher spawn rate.

Blaines explains this in his video where he mentions the

much higher spawn rates

for current recommendations with a full dex.