I would show the photos to the Deere service manager before having them pick up the deck. It may not be something they handle in house and they may want to refer you to a shop who does fab work. If the Deere dealer will repair it, I would want to get a solid price estimate in advance to avoid any surprises.
Also, with the impact the deck took, perhaps the deck has other damage or is twisted. It took quite an impact with a lot of weight / force to bend that short of a brace that severely and to break the welds.
This is why I think the Deere dealer is likely to defer to someone else on this. If they were to repair it and then find out the deck is damaged and needs to be replaced, they suddenly are into a replacement deck as the simplest solution. They would also likely price out the deck housing cost, but the labor to swap over all of the pieces will quickly make the new decks cost more attractive. This isn't really the dealers area of specialty, but perhaps they will handle it, or they can suggest who will.
If the dealer won't handle the repairs, I would visit with established small engine / repair shops and show them your photo's. When you share the photos of the deck damage, you will get one of two quick responses;
1. "That's not something we do"........as they have a look of "No thanks" on their face, or......
2. "Hmm, All I would have to do is to remove that brace, put it in a press and straighten it and then re-weld it and get any needed parts from Deere".........
Number 2 is your place......Hopefully, you have pallet forks or at least straps for picking up the deck and loading it to get it sent out for repair.
I would imagine your homeowners policy or if you have the tractor insured, that the tractor insurance coverage may come into play if the repairs end up requiring either a new deck housing or a replacement deck.
Also make sure to get a specific time frame for when the repairs are likely to happen. In our area, the good shops are booked out 3 weeks right now............