It seems like you are talking about two different things: the ability to send TTS to Alexa devices to speak (and possibly some advanced features like commanding Alexa-connected devices with what would otherwise be voice commands via text) versus the ability to add Hubitat (or HASS) devices to Alexa for voice control of those devices via Alexa. My understanding is that HASS per se does not provide the former, though a (free) community integration/component does. This is similar to Hubitat. There is unlikely to be anything official here because Amazon does not officially support this, though to date, at least one unofficial solution on each platform has continued working.
My understanding is, further, that as mentioned above, the latter (voice control by integrating non-Alexa devices into Alexa) requires either doing it yourself or a Nabu Casa subscription. This is included, built-in and free, on Hubitat.
If you have a functional HASS setup with Alexa Media Player (the component I suspect you're talking about, or possibly anything else that works similarly), support probably could get added this app/driver for easier integration, and that would certainly make sense if you're already using it. But, that's not my call, and I don't use it myself or have a need to look into that. I do keep a test HASS box around for basically only this purpose (because it's still easier than setting up something else for only this) and wrote a Hubitat driver to get TTS from Hubitat into these devices (or possibly anything else that works similarly): [RELEASE] Home Assistant Alexa TTS Proxy (another Alexa TTS option). It's pretty basic, but it fills this one specific need I have, and maybe it would work for you, too, if I'm understanding you correctly (at least until something better comes along, if it does 
).
