Is this allowed or a thing Would I be able to swap from Xbox one -> Xbox series S and keep all my progress and DLC’s ?
With xbox everything comes over because Xbox has your profile and purchases saved in the cloud linked to your Gamertag and your DTG account keeps track of ingame progress and stats. Pity the same can't be said going PS4 to 5
Basically, yes Because you're staying on the Xbox platform all your licenses transfer, and with Xbox you can transfer your progress as well.
You can do that because you are simply transferring over Xbox gen 8 train simulator world to Gen 9 due to the content being located in the cloud. Have the base route Southeast high speed with the Brighton main line you are going to see South-eastern part filled and gain 375 services from East Croydon to Redhill
I’ve recently upgraded from Xbox One S with TSW 2 to series X with TSW3 BCC and I’m massively impressed. High speed routes especially.
Much more detail on BML. Especially Battersea power station. I’ve only been on it once. SEHS is smoother. You can see further into the distance. Not so much lagging
With Xbox, I believe everything just moves over as long as you use the same Xbox account. I've never owned one myself but seen others mention how easy it is. Trying to decide whether to jump sides and get myself a Series X right now... Better than the system (or lack thereof) on PlayStation. You need a degree in rocket science to move your save data from PS4 > PS5.