The move to Beta was a step backwards or going from a 4t to a 2t?
It's good enough for Jordi Pasquet to ride it in WTC events, maybe Doug said "Develop the 4t with JP and I'll ride it when it's ready for me"
Doug switching to the 4t are just rumours at the moment, it might happen, it might not.
Why would Beta want to follow what Honda/Montesa did anyway? It doesn't make sense to use your best rider in a development role (especially if he's in his last years at the very top). Beta along with Doug & Co. would have have wanted the best possible chances at the earliest point in time, not in 3, 6 or 12 months - I certainly don't think their decision was a bad one, as his results to date might well have been worse on the 4t.
Honda did it but they could afford the risk, as they had Doug, Fuji and Freixa (?) at the time...