Using yesterdays 0.5.8 nightly on MacOS 12.1.
Currently it is possible to enable/disable tooltips in Settings > Editor. I have this disabled as I do not want the tooltips popup when I move my mouse over the page randomly.
But sometimes you want to preview a linked note without opening it. It would be convenient when the combination of hoovering over an internal link with the mousecursor and a CMD key press would popup the tooltip/preview even though you have disabled the earlier mentioned option.
This is the same way Obsidian does it but another hotkey is fine.