You are incorrect.
but, please, establish the truth of your claim.
Here is a basic argument that you probably can’t refute
Choose Mercy and latch your beam onto someone. Now move your screen such that the beam target is no longer on the screen or is no longer centered at all
See how the beam stays latched on? That’s a lock-on
Now do the same with Moira.
You see how the beam stops doing damage when the character is no longer centered?
Not a lock-on
I look forward to you attempt to show how this is wrong