It's certainly possible. They do have some of their own apps up in the Play Store to make it easier to update certain functions of the phone without needing to wait on the carrier's approval for a mass OTA update.
Any reason you would want an HTC file browser vs. using one of the options in the Play Store?
Because of KitKat 4.4.2.
Google has killed most of the functionality of the microSD card.
Any THIRD-PARTY (Non Google or HTC) may/will have issues.
Third party apps are limited to writing, and reading from, folders that the app itself has created.
So a photo editing app cannot go to your external sd\photos because it did not crate that app. Similar with anything else.
INCLUDING file explorers! Which we see as basic user interface...being able to move folders and files around/copy/delete, etc.
But KK see this the same way as an app trying to access a folder that it's not "allowed to".
So you cannot use something like ES Explorer that way it worked (well!) in JB.
AND...because HTC did not include a stock file explorer (as Samsung does)...there's no way to access and work with files between internal and external memory the way you're used to doing it.
Since HTC obviously know far ahead of release that they were using KK, it seem like a huge oversight that they neglected to include this basic and essential app on-board.
I'm hoping they realize the error and push out their own "app" for this so I don't have to root.