Thomas started his last game for PSV before being sent off at about 20 mins.
It was a huge game against 3rd placed Alkmaar. PSV coaches wouldn't have started Thomas in a tough Eredivisie game if he wasn't nearly back to full fitness.
I'm sure NZF and PSV will have a chat, but now that Thomas is suspended, I suspect what he actually needs is more playing time. In an international friendly you would hope there is less chance of say dangerous tackles flying in, than a normal Eredivisie game. Plus is a short flight from Holland to Ireland. So why wouldn't he be involved with AWs.
I imagine Hay will experiment against Lithuania a bit, but will want something close to a top side playing Ireland. Top side haven't played together for 2 years (Peru late 2017), and Eire are a good tough European team (even their 2nd string).
Put out a bunch of kids against them and it could be embarrassing.