Why doesn't Photoshop 26.4.1 create a Pantone channel when I place an elliptical path

It seems to me you either misremember or your descriptions are misleading. 

In Photoshop there is no spot color vector data (so far) – period. 

If the cutter can recognize paths in a tif/jpg/psd/… as a cutting line that would be another matter. 

If I'm not mistaken it was CS, I've been working with Photoshop since version 2.5. So I'm not sure.

»But I've already done this with other versions of Photoshop. When I created a vector in Pantone, it automatically created a Spot channel.«

That does not seem likely or even sensible – after all what good would a channel (instead of vector data) be for the die cutter? 

In which Photoshop version do you think you did this?

Vectors don't use spot colours in Photoshop.

You can assign a Pantone or HKS or other color book library to a vector, but it's going to use the document colour mode, it's not a spot colour as would be the case in Illustrator or InDesign. Spot colour channels are a separate, totally different thing. I have never known Photoshop to automatically create a spot colour channel for a stroked vector.

But I've already done this with other versions of Photoshop. When I created a vector in Pantone, it automatically created a Spot channel.
Now I have to create a Spot channel and the vector or selection that I create brings the filled element.

Spot colours in Photoshop are raster based. Photoshop vectors can't use spot colours. So this isn't possible in Photoshop.

You need to use other software to set the cut/crease vector path to the desired spot colour name.