Emailed Titleist and they responded very quickly
The stock swing weight for the T200 irons is a target of D1 for anyone else that is wondering

I just received my T200's with Modus3 T105's and they came out at D0. I'm guessing the reason is that they're basically a 1 club stronger loft, so if you take a 1/2" off (to resemble a standard club) the swingweight would be around d2-d3.

Shortening club length will decrease swing weight 3 swing weightpoints so D0 will reduce toC7

Sorry, forgot to indicate my response was refering to a 1/2" rediuction in length = 3 swing weight point reduction

I believe with a standard 115-120g shaft you will see D2 however when you go into lighter shafts for every 10g reduction in shaft weight you lose 1 sw point…. Therefore if you went from a 120g shaft to a 95g shaft it’s 2.5 sw points…

I had a hard time wrapping myself around us because I custom ordered a set of irons recently, and when I got them, I put them on my scale and they were extremely light

The one thing you need to take in consideration, swing weight is very much an arbitrary number, and it was designed for golf clubs with the old hickory shafts initially with my new irons I wanted to take them apart, and I wanted to swing them to where they should be even though I use larger grips , etc.

The truth in the matter there though is when you start to put tip weighting into the shaft, you are going to effect the cycles in the shaft so if you were to add 6 g you would in essence drop your CPM of the shaft by 1/3 of a flex Which can directly affect how the shaft works and how it launches, etc.

The only thing that made sense to me, I had to take an iron with a standard weight shaft and a 50 g grip and then I had to get it to D2. Believe it or not when you play that club and then you play one with a lighter shaft 100 g for illustration purposes that one will settle out at D0. However they feel very similar in feel in your hands

Excellent post