A full list of 50+ Chronomancy spells, plus related monsters, items, backgrounds, etc, can be found in the comments of my Chronomancer (Wizard) subclass here.
https://www.dndbeyond.com/subclasses/6582-chronomancer

Chronomancer, Version 2 - [https://www.dndbeyond.com/subclasses/522102-chronomancer]

This spell feels kinda silly since:
Dodge is already an action that gives enemies disadvantage.
And then True Strike (can't believe I'm giving it any credit) can already give advantage on the next hit, except it can be used on the next turn and this can't. 
Its sorta redundant to have something like this.

As you mentioned, there are two distinct actions a player can already take to produce either of these two effects.

This spell, however, only costs one action and results in the option of either one.  Imagine taking the Dodge action only to find an opponent never attacks you that round.  You wasted an action.  But wait, if that's the case, imagine being able to change your mind after the fact and say you actually cast True Strike last round instead, so let's turn that wasted action into Advantage now.

This spell provides better action economy for you in either of these cases, and is thus objectively better than either.

It may not be an awe inspiring cantrip, but it's far from silly or redundant.