[Google Pixel 8 Pro] eltoddo:
Hi @Old faithful, sorry if this is too late to be relevant to you. If it is, I would still be curious to hear how things went in your situation. Even so, I still felt compelled to share my experience currently facing the same question, in case anyone could use the info...

Just went through the same thought process myself. I know that for SIM Unlocks, if you phone is not fully paid for yet, your carrier, if you got the phone from them on a subsidy, will not allow another SIM in your phone to prevent you from getting a good deal and going with another carrier. The logic being: you paid for a device and service from us, but you asked us to cover the cost of the device for a term (usually 2 years), so it's not your phone until you have covered the phone's cost. Anyone not seeing how that's fair isn't thinking clearly, but I know a lot of people (previously myself) don't think so. Avoiding the controversy (out of scope for this post), and to offer a knowledgable answer to your question, I think carriers selling "locked" phones only applies to SIM locks and not bootloader locks, Verizon being the noted exception. The lack of hard documentation to this effect left me questioning it enough to push me to buy my next phone from Google directly. It's a big up-front pill, but I found a way to swallow it.

I expect that buying the Pixel 8 through Telus will lock the phone to your SIM for the term of your subsidy. But you "should" be able to unlock the bootloader following normal procedures at any time during the subsidy period. But Carriers do reserve the right to restrict this, and do so inconsistently and arbitrarily due to changes in market conditions. As pointed out, some like Verizon apparently do excercise the right to keep the bootloader locked, likely for support logistics. That being said, if you opt for a carrier subsidy, consider how much it would really suck to need a replacement phone sooner. But that's the risk you're taking. You'll then be on the hook to do whatever the carrier requires to settle your current phone, which would hopefully be limited to just a buy-out on the remaining subsidy, or continuing the subsidy till they're satisfied your absent phone is paid. But then you'll need a new phone too! That's an even tougher pill to swallow. Just ask anyone whose had to pay for a wrecked car long after the wreck. It was too much potential frustration for future me. Plus, none of the carriers (in Canada at least) are really offering a discount that compellingly justified buying the phone from them, to me anyway.

TLDR; From what I've read, I think the Telus Pixel 8 phone, and any other carrier selling the phone, will come locked, but should allow bootloader unlock at any time. Keep in mind any time a carrier subsidizes your phone, you don't own it till you paid for it, and you have no legitimate recourse but to conform to their terms on this point until the phone is paid off. Buy the phone outright, and you'll never deal with this nonsense.

BTW: Luckily Google themselves supports the idea that you should be able to unlock your bootloader and makes a reasonable option to own the device outright available. Pixel 8 Pro (at this moment) is $250 off in Canada direct from Google, making it ~$1050 CAD. Being a Google One subscriber means you'll get a 10% Google One credit. For me, since I ordered the 512GB model, which means I'll enjoy a free year of 2TB storage that I normally pay for anyway. Far more compelling, to me anyway, than any deal from a carrier. For the record, I still would have gone with Google if there wasn't a 10% back benefit. I was sold on no carrier involvement. As I believe you'd agree, I just want to own the damn thing.