I wouldn't know what to call this, a dimension meld? A uniting of the world of the spirit with the physical world? It's obvious something really different will happen. It's beyond me what it will be, but we know it will be wonderful.
The dimension meld or blending of spiritual/physical realms that you propose for the Revelation 21 new heaven and earth is very interesting!
I had previously heard it proposed that Rev 21:1 refers to a "big crunch" - the reverse of a "big bang", forming a new singularity out of which would spring a new heaven and earth. But being particularly "keen" on higher dimensional dynamics, I do want to examine your theory much more closely!!!