I'm forgetting exactly what I heard where, but wasn't there something about ranger pets getting larger, and getting armour or something like that in one of the things that has been shared?
I believe their words were something like: "Pets will become larger, stronger, their names will change and some may even get some armor."
So my reading in this is progress type: Wolf - Big Wolf - Dire Wolf - Worg - Armoured Worg
I also like the idea of rangers with one faithful animal, even if they can sometimes ask others to help out.
It have its charm, doesnt it?
Having an Elf who is followed with his good friend Panther for last few years and countless adventures.

Perhaps he will be locked to an increasingly powerful bear form? Probably unlikely, I know.
I wouldnt advocate for locking ... neither with pets, nor druid forms.
I just think they should remain relevant.
Like ... hells i dunno ...
We know Druids will get displacer beast and owlbear right?
I am personaly kinda oldschool and dont like my druid to turn into monstrosities, even tho they are concidered "animalistic enough" by Larian ... resp. WotC.
Easy fix imho ...
Is to give Bear updated stats, as you get Owlbear ... so they have same attack and hp ... and difference is just either skin, or different actions.
Same goes for Displacer beast ... we know that our druids will be able to transform into Panther ... just make their stats same.
But i realize its much easier to just give us stronger forms, then making several versions of the same.

//Edit:
I still want Scratch to be available as an animal companion.
And, of course, I still want Shovel to stick around permanently.
Also this!
Both of it ...
And Owlbear cub!