"My father supported him at school, and afterwards at Cambridge; -- most important assistance, as his own father, always poor from the extravagance of his wife, would have been unable to give him a gentleman's education."

IMO this indicates that Darcy thought that Wickham was entitled to a gentleman's education; that it was not just a whim of old Mr. Darcy, or old Mr. Wickham.

Then after stating Wickham lack of moral and telling about the resigning of the living Darcy says:

"All connexion between us seemed now dissolved. I thought too ill of him to invite him to Pemberley, or admit his society in town."

Darcy didnīt invite Wickham to Pemberley or associate with him because Wickham's conduct, not because he considered him a servantīs son.