Microsoft is a commercial client. I have no doubt that they are paying MeteoBlue for their service. Their global NEMS model is available twice each day, as soon as the calculations are complete, typically around 0530 and 1730 UTC. Their model output is probably encoded in GRIB format, which is the standard file format used for computer weather model output, no matter what the source.
Meteorological forecasting services like MeteoBlue pride themselves on providing their data “on time” to their clients, which include agricultural and energy sector users for whom timely updates are very important. I can’t imagine them deliberately delaying it for any reason.
Microsoft probably has to further process the model file to convert the data into a form the sim can use, and then load it into their Azure servers for streaming to the game. If there is any delay, it is probably happening at the Azure end.
It is possible that MeteoBlue pushes the completed forecast file to Microsoft when it is ready, but probably more likely that Microsoft initiates the download.