Nice

Option 1: No Change

- Probably how it would actually happen.

- No long lasting effects on their relationship just a good shoulder pat and moving on to the next thing.

Option 2: Distrust

- He was originally able to separate Meg's the decepticon and Meg's the autobot. "it was in the past" kind of way.

- But the arc causes him to merge the two and re-remember Meg's atrocious during war causing contempt. Especially if Meg does attack them.

- Op doesn't mean to be holding a grudge against Meg's and he feels guilty for having these feelings. It doesn't change the fact he now doesn't trust him, despite trying to hide it. (Accidental passive aggressive remarks)

Option 3: Obsession (Self-indulgent)

- Optimus finally has Megatron back and HE LEAVES HIM AGAIN!!??? I would crash out sooo bad. Imagine having a "friends to enemies to lovers to enemies to lovers" pipeline.

- If fate wasn't kind enough to keep him here then he will MAKE him stay.

"This is my stop"

Old people have bones made out of crackers and insist on carrying an entire wardrobe.

A good stretch after a long day of patrol

...

I thought it would be interesting to switch up the trope of younger Orion and old man Optimus.

Also I think the Matrix doesn't necessarily age OP but transforms him to his "prime".