Not what I remember. Always when I chose to open a .dng from lightroom to edit in photoshop it opened in Camera raw.
I can't help with what you remember. When you use
Edit In Photoshop with any raw file, LR sends instructions to Adobe Camera Raw to process it and provide a rendered image in Photoshop. The two products must be in version parity and
should be in version parity; otherwise, LR pops a warning dialog informing you of this mismatch. Only then will you have the
option to override this and open an Adobe Camera Raw dialog. Otherwise, there isn't an Adobe Camera Raw dialog
by design; there is no need for that dialog either.
If you want to access the Adobe Camera Raw dialog and only use LR as a DAM (why, I have no idea), use the Open command from PS, drag and drop over the PS icon etc. Then LR is out of the picture.