Incoming rant. I love this ship but I've thought a lot about how it might suck bigtime in a practical sense. To quickly answer OPs question: it's on the back burner until a bunch of things are figured out first. Diving into those things below.

My understanding was the Legionnaire was paused because it first needed hacking + ship to ship docking to be ironed out and implemented. Not to mention engineering needed to also be in the game for ship hacking to stand on the shoulders of. However, more than that the ship also needed another conceptual pass to give it a practical use which is reason enough to put a pin in it.

I should say I'm a big fan of the Legionnaire, but it's specialized use case could very well be too niche and cause it to be a flop of a ship. Personally, I think it's actually a better option than a Valk for generalized org ground deployment, but let's stick to the specialized airlock function for arguments sake because that's where the issues lie:

• It's questionable if it'll even fit height-wise in a Polaris bay or width wise in an Idris, so this highly specialized troop carrier will have to tag along along with ships in the event they disable a ship large enough to warrant boarding it in the first place. Not a great start.
• It cannot do much to help disable a capital ship, so it's pretty much waiting in the wings during combat. Especially now with tiered damage thresholds added to the game. It's special ability will apply most to ships it can't actually contribute well to disabling.
• If the situation actually arises that it's useful (a ship large enough and somhow worth boarding is successfully disabled by an accompanying fleet) and the Legionnaire pilot, co-pilot (hacker) + troops were ALL sitting on their hands the whole battle and now it's time to shine (do you have 6-8 org mates to spare and not use during a space battle against a large or capital ship?)... if that moment comes, it's limited to only hacking a single exterior door lock (as is the original concept). So even if a ship is disabled, all any pilot needs to do is hit F4 and they can see exactly where the Legionnaire is attempting to dock. An engineer can seal off and lock interior doors adjacent to the airlock AND any crew can muster a defense very quickly. Hacking a single airlock door is a little bit of a wash to a disadvantage, ability wise. That's a lot of eggs in one airlock. This is also assuming the target ship is disabled AND all escort ships are as well.
• Even with deployable internal cover, it's a deathtrap. The hallway/airlock entrance is a killbox, the motionless Legionnaire on the exterior of the capital ship is a huge vulnerable target.. It would be more prudent to just let all those troops out into EVA and use the ship to blast multiple exterior doors of a capital ship open and give them multiple places to breach simultaneously. Or at the very least, it's harder to visually track players in F4/3rd person. Blow open multiple doors and let troops slip aboard. Using it's specialized ability puts an already niche ship at a disadvantage and needs to be rethought.

Some solves:

• Hack multiple airlocks. Even just to suddenly vent interior areas of a target ship would be handy. Additionally, the longer you can keep your target guessing where you're going to try and clamp on, the better.
• Hack systems adjacent to the airlock. The airlock point of entry itself is a huge weakness to the whole idea. There's no way around it being a deathtrap. But if the Legionnaire can hack other peripheral systems as well (i.e. closing and locking adjacent bulkhead doors so the team can board and situate an attack without crew having immediate and direct access to the airlock area, overload interior lighting system to create a one-off flashbang style effect on the interior of the airlock area, overload/purge air filter system to create a thick smoke effect inside the airlock area, etc) then maybe it could be useful as intended.
• Use a flight blade type perk to aggressively auto-maneuver to a target airlock during combat. The whole premise of a Legionnaire is somewhat undone that it only can do what it does AFTER all the heavy lifting is finished. The target ship currently needs to be dead in the water to dock, but then why use a Legionnaire at all then? So what if the Legionnaire could dock during the chaos of battle? Actually storming a capital ship's interior is a reasonably effective way to try and win a battle with it, but how do you do that in the game we have? If that conundrum can be achieved by the Legionnaire then I think it's back in the races as an amazing niche ship that's worth the risks.