Can research project scholarship offers ever get retracted?
Well, probably yes, if they find out you have a "rap" sheet for dealing in x,y and z etc etc.

But I think they have just been busy so have not replied, and are still looking forward to welcoming you on that date.

You may find that you receive an email with lots of info as you are on some other mailing list to get initial information... The wheels sometimes grind slowly...

Best of luck!