Q.mature grafted weeping cherry
We have 10-year-old pink-flowered grafted weeping cherry. The top branches were never pruned, so they are growing straight up, but the bottom branches are weeping. So basically, two tree varieties are growing from the existing trunk. Is it far too late to crop the straight up branches from the top? I am guessing “yes” since the upward branches comprise the majority of the tree. Perhaps pruning the minimal weeping branches is the best advice at this point? Other than the bizarre shaping, the tree appears healthy and the entire tree flowers in the spring. Thanks for any input.

You can try to thin out the top of tree with some pruning to visually make the tree more appealing.
Here are some links for you.
https://www.gardeningknowhow.com/ornamental/trees/weeping-cherry/pruning-weeping-cherry.htm
https://www.gardeningknowhow.com/ornamental/trees/weeping-cherry/weeping-cherry-growing-tips.htm