I can't find any references anywhere to anyone asking him about it since he won the election. Before the nomination, his answers where classically institutionalist. After the nomination, he refused to be specific and said I'll let you know after the election". That doesn't appear to have happened.
>Democratic presidential nominee Joe Biden again ducked questions Thursday about whether he would seek to add seats to the Supreme Court, telling reporters he would not address the issue until after the November 3 election.
For me personally, when I combine that with his institutionalist remarks before he became the front-runner in the D primary, leads me to believe that he's not in favor of it, but tried to hedge once he won the nomination to avoid another irritation to progressives.
I do understand that your interpretation may be different.
