How to reproduce:
1. Open the attached "1327461_Repro" project
2. In the Project window select "New Material"
3. Observe the Inspector (Window->General->Inspector)

Expected results: The "Vector 2" variable has 2 inputs (X and Y) and the "Vector 3" has 3 inputs (X, Y, and Z)
Actual results: Both "Vector 2" and "Vector 3" variables have 4 inputs (X, Y, Z, W)

Reproducible with: 7.5.3 (2019.4.24f1), 10.4.0 (2020.3.4f1), 11.0.0 (2021.1.3f1), 12.0.0 (2021.2.0a12)

Note:
- While both Vector variables have more inputs in the Inspector than should they do not affect the Shader Graph if changed