Just because you can, doesn't necessarily mean you should. You may not find it as simple in the beginning, but if you invest time and dollars toward adding HA instead of an IKEA DIRIGERA hub, you'll not only be able to add everything IKEA and Matter, but you'll be able to add a massive amount of other manufacturer's devices in the future, regardless of what radio or communicaiton protocol they use. I've found that between HA and Hubitat, there's nothing I cannot add to my smart home.
The connection from HA to Hubitat is via Home Assistant Device Bridge and if you need to go the other direction, there's a Hubitat to HA integration too. I use both for various scenarios. I have not found a single worthwhile hub, bridge or device that cannot be intigrated with relative ease. It's pretty darn powerful if you're willing to learn how.
Keep in mind that Matter lets you connect devices, but one manufacturer will limit what is exposed to another via Matter so that they can keep you in their app/ecosystem to control your experience and keep harvesting your data. It's worth a lot of money to them. If you connect via Hubitat or HA, the experience is typically unlimited and completely private, unless a Cloud API is required for connection to the device (i.e. My Yolink hub).
If you're currious, my setup looks something like this.
Hubitat C-7 x2 <-> Home Assistant
<-> Hue Bridge
<-> Lutron Smart Bridge Pro
<-> [Node.js server] <-> Insteon hub
<-> Homebridge
<-> [Cloud API] <-> Yolink Hub
The Hue Bridge has direct local links to both Hubitat and HA, and the Yolink hub has cloud links to both Hubitat and HA. In other words, either can control them and get status. All others are linked either via Hub Mesh (between my two active Hubitat hubs) or one of the two HA integrations. It would likely be very confusing at first if you looked at how things communicate back and forth between my various hubs and bridges, but over time I've come to know instinctually which direction or integration is needed for a particular task or device.
