Since 2011 HTC has permitted bootloader unlocking on some of its models, allowing developers and enthusiasts to tinker to our heart’s delight. HTC stood alone among other OEMs in providing both unlocked and developer edition devices, with the developer edition devices retaining much of their warranty despite unlocking. That changed with the HTC 10 which dropped the Developer Edition but retained its bootloader unlocking policy on the Unlocked model, in a practice that started with the A9 and was prominently displayed on the “Meet the Unlocked…” page.
It would appear that HTC may be taking a reversal of policy with the text boldly proclaiming “Your HTC warranty even covers bootloader unlocking on the HTC U11!” being removed as of the time of this writing. This text has also been removed from the HTC U Ultra, and HTC 10 page. Thanks to the Internet Archive, we can see that these pages were updated sometime in the past two weeks since all three had the text as recently as June 29th, and the verbage was even changed on HTCDev in relation to the U11.   
What this means going forward is anyone’s guess, as a major perk to purchasing an unlocked device from HTC was the ability to unlock the bootloader without immediately voiding the warranty. This could just be a clarification and tidying of the information displayed and the prior policy might still be in place. However, it could also mean that HTC will no longer be as generous in its support of unlocking its bootloaders in the near future. At this time it is still unclear whether such a move would affect HTC’s global unlocking policy as well. It is still important to note that the text – quoted below – on HTC Dev has not changed as to the possibility of voiding of the warranty for using the tool and to repairs stemming from the modifications. But this text is vague and not quite the explicit amd encouraging statement found on the earlier linked pages.
“It is our responsibility to caution you that not all claims resulting or caused by or from the unlocking of the bootloader may be covered under warranty.”
Bootloader unlocking has been a contentious topic for quite some time with many OEMs attempting to void your entire warranty just for unlocking the bootloader, even if the device’s failure is totally unrelated. At the same time though, some users push the boundaries and end up bricking their devices yet still attempt to claim it under warranty as a hardware failure. This causes manufacturers to look at those who like to tinker differently, and has likely further justified OEMs’ decisions to keep many variants locked down, especially in the US.
If the company did change its policy it would be a major step backwards in terms of supporting developers and could kill an already fledgling (but tight-knit) development community. But, this could simply be an unrelated decision, perhaps prioritizing or emphasizing the features that more mainstream customers understand and appreciate. We have reached out to HTC for more information and will update this article accordingly.