Theses are my Warlord class recollections:
Near the end of 3.5 WotC published a miniatures/warfare type supplement. It introduced the Marshall and Healer classes. The book was not well received, except for the Marshall class. 4e came out not too long after, and the Marshall moved into the new edition, renamed Warlord. During the 5e playtest, people asked about the Warlord class because it had been popular in 4e. They were told the Bard and Battle Master fighter could fill the that role. This did not sit well with the Warlord fans at all. Much angst and anger and squabbles with fans who didn't care about the Warlord.
Eventually, word came out, (or maybe just rumours) that Mike Mearls did not like the Warlord, so not going to happen.
5e has only ever added one full class since it's publication because it relies on subclasses. So, no Warlord. Whether there's a subclass that can satisfy the commandery itch is subjective.
Many 3rd party publishers and D&D adjacent games have created Warlord type classes, so there's definitely a demand. And if you are a fan, it's easy enough to track one down for 5e. WotC's not going to do it. Personally, I like Commander style classes.