First, let us say that Mary of Burgundy had been born a boy, for whom we'll refer to henceforth as *Philip IV. Let's also assume for one moment that Charles the Bold's career unfolds more or less as in OTL, and he is killed at Nancy in 1477 and succeeded by *Philip IV, who manages to make peace with all the people his father pissed off and focus on increasing his own wealth and power.
Taking all this into account, what are the chances that *Philip IV or one of his sons could displace the Habsburgs and gain the Imperial Crown in the next few decades? It seems that the Duke of Burgundy, with his wealth and power, would be very well placed to make a bid for Holy Roman Emperor, especially considering that at that time the Habsburgs would only have been elected to the imperial throne for one or maybe two generations...