To use home assistant as a main server or hub to link with your google assistant, google home, amazon alexa, siri with broadlink. I recommend you check from home assistant component page for broadlink switch.
Get devices to control by broadlink into HA first, then again check from home assistant for other components for google assistant, alexa, homekit. All these components can be add into home assistant.
If you choose to use home assistant + ha bridge + broadlink. At final stage there are many components that need let’s encrypt which use port 80 (this port also use by ha bridge) on your pi for registration. Then you will end up miss of using many components that home assistant support.
Another method is to create a script for each set of IR commands (i.e. change to next channel), then expose this script via the Google Assistant component.
After a resync with Google Assistant, the script can be launched by saying “start [scriptname]” (i.e. start next channel) or “turn [scriptname] on” (turn next channel on)