I said to myself back when Gokaigers came out. That from there on out. They should have every future team able to transform into any of the previous squads. Glad to see it in this one.

Or is this still tied into Zenkaiger or something?

I think it's still tied to Zenkaiger, especially considering it's the Sentai Gears being turned into the Avataro Gears that let them become previous Sentai rangers.

So, with the recent monster being Lupinranger themed and a thief, and the previous being ToQger themed and tied to a woman de-aging herself, will all the monsters' human hosts have a thematic tie to their Sentai?

Well seeing as they haven’t introduced another method to acquire the remaining 43 Avataro Gears…

I meant that will the human hosts always retain a trait pertaining to the sentai their monster is themed after?

The few episodes we have so far would suggest YES, though some comparisons may only be tangentially related. The one who became a ToQger-Themed kaijin didn't have a direct connection to trains, though the most recent was a thief, which fits the Lupinranger theme.

She didn't have a connection to trains, but she was obsessed with becoming younger, which ties to ToQger's plot reveal that the rangers are all children.

Thought it through, and the obsession could loosely tie into the other thematic element of IMAGINATION! I suppose this suggests that even if someone doesn't echo the physical/surface theme, they could echo a Sentai another way.

I thought for sure the character was going to become a straight up child. Definitely picked up on the ToQger reference.

Also excellent casting there, the actresses that played the various stages of the woman were very convincing.

I'll accept a simple majority.