1.25" receivers have a capacity of 200 lbs. The rack you're talking about weighs 58 lbs. and can carry two 80 lb. bikes, for a total of 218 lbs. Putting a 2" adapter in doesn't help the math, in fact, it makes it worse by pushing the rack and bikes further back, creating a longer arm to for all that weight to bounce up and down on.
People do things and even get away with them for a long time. Until they don't. If you were to do this and the rack broke, sending bikes all over the road causing an accident, you might think you could sue Hollywood, but you'd be the one on the hook for any liability.
TT