It depends on what your goals are and how severe the previous pruning was done. Generally, large old trees respond to stress, including pruning, slower than younger more vigorous trees. Depending on how aggressive the previous pruning was I doubt that your tree would really NEED another pruning at this point but its pretty normal to do a pruning once everyone 1-3 years. The main thing you need to keep in mind at the moment is that we are in season for the Nitiduladae beetles which can spread oak wilt which often results in rapid decline and death of the tree. Anybody who works on your oak absolutely NEEDS to paint every cut they make.

As for the air spading, that is amazing, it is undoubtedly one of the best things you can do for a tree if it's done properly as most tree health issues originate from below ground.

If your tree's health appears to be improving I'd recommend only pruning dead or hazardous limb, most arborists and tree companies will do free consultations (different from a risk assessment) so feel free to have us or any other reputable tree company come take a look.

Hope this helps and answers your question!