I wouldn`t be so sure.
The Church would be opposed, of course, as with any kind of reformation, that`s why the reformators forged their own churches.
"The nobility" would be mostly opposed, yes. But they´re not a uniform class. By the XV century, many less important knights experienced a crisis of their own, too. How some of them united with a social revolutionary movement and fought alongside them can be observed in the case of the Hussites. If the future state finds a meaningful role for them - could be interesting.
As for "the bourgeoisie", once again I´m not so sure. If by socialism you understand collective ownership of land and syndicalist organisation of the crafts, then lots of crafters in the towns are on your side. (They were the basis of radical Hussite groups like the Taborites, too.) In the towns, the guilds fought for representation and a share in municipal power against mercantile patrician dynasties. In some towns, they had won, while in others, they were still struggling and could have been won over for the cause of revolution.
The difficult thing is the absence of an abstract political-economic vantage point on the entire matter, one which would unite petty crafters and indentured servants, or in more Marxist words, the consciousness of a revolutionary class.