VanLifeDreamer, sorry to hear of your delays. We get our SMB this month and have seen similar delays with regard to pandemic supply chain disruption and SMB-West working at keeping Covid out of the factory by sending folks home to quarantine, with pay I understand, so a hat tip there for a small 60 person company.
The forums I visit say a custom van build has been 18+ months wait for some time now because of the popularity of "van-life" and pandemic-driven sales.
The other difficulty, as of a few months ago (perhaps you know?), is automotive semiconductor shortages. As far as I know, every manufacture has furloughed workers and either slowed factories or closed them because of the lack of semiconductors here in the States and abroad.
An overview on this found here: https://bit.ly/3kUa6Bt
So if your Sprinter isn't already built, you may see delays from Mercedes.
Hope the thoughts help.
Hang in there and good luck!