I think there is a mis-perception going on here. For Win 10 Mobile, the OS is WaaS and only Firmware changes need to be submitted to carriers.
Going from 10586.63 to 10586.107 is an OS bump. Microsoft gives that to Alcatel OneTouch. Alcatel tests it. If there is no Firmware addition, they need not submit it to T-MoUS and can push your OTA from their end or authorize Msft to do so.
So, then, should I make the assumption that from what you have said, that it's Microsofts fault that the owners of the XL are not able to get the .107 update, and that it's not a result of TM locking out any updates for the phone, and that's why someone has already figured out that the only way you can get it is by rooting the phone to make it think it's a Nokia Lumia #xxx and not an Alcatel XL (see Fiery Fix thread in this forum), and that you need to hard reset it after the upgrade to send it back to thinking it's an XL. Somehow, and it may just be me, this smells more like TM than MS.
Maybe (?) Alcatel OneTouch didn't get the memo and they will (would have) sent it to T-MoUS as they would for an Android handset, or even a WP 8.1 device. But for the OS bump under Win 10 Mo, T-Mo need not be involved.
So, then, should I make the assumption that from what you have said, that it's Microsofts fault that the owners of the XL are not able to get the .107 update, and that it's not a result of TM locking out any updates for the phone, and that's why someone has already figured out that the only way you can get it is by rooting the phone to make it think it's a Nokia Lumia #xxx and not an Alcatel XL (see Fiery Fix thread in this forum), and that you need to hard reset it after the upgrade to send it back to thinking it's an XL. Somehow, and it may just be me, this smells more like TM than MS.
The last wave of phones to be added to WDRT do not seem to be enabled in Insider as of yet... Certainly the BLU Win HD LTE people have tried and failed daily to get Insider Builds since being added to WDRT. No one knows yet if they will be added or when.
So now it comes down to what is a Production Build. That is what Microsoft would push OTA. So far as I know .107 is still not on the Production Build ring. Once a build makes the Production ring that is a preview before the OTA and would signal a build will get pushed shortly.
WaaS has a beta test hierarchy. After internal Msft use > Fast Ring w/ feedback and bug fix > Slow Ring w/ feedback and bug fix > Production Ring w/ feedback and final tweak > OTA.
Hopefully someone will correct me if my understanding of the process is at fault.
Sorry for the double post, but I may have confirmed that carrier intervention is still going to be a thing with T-Mobile regarding Windows phones via twitter.
According to them, the latest version for the Fierce XL is 10.0.10586.63. When asked if MS has even submitted .107 for certification, they stated "not yet! Stay tuned!"
I'd show you guys the conversation on Twitter, but my profile pic is that of <reference and link redacted> and I'm honestly surprised T-Mobile even replied to me in a serious manner in the first place.
That being said, it looks like your best bet is to enroll in the Insider Release Preview ring if you want the update now. Otherwise, you'll have to wait for MS to submit it, and then for T-Mobile to approve it.
Whenever that'll be.
(Never)