Hi Chappy
You’ll find enough company walking out of Sevilla at your chosen date. (Or at least further along the way / but not crowds !!!).
There will be many preparations in Sevilla before you leave there as Semana Santa 2025 starts 13 April.
It is a great time to walk on the Vdlp - you will find most villages etc will have their own Easter processions etc. Many people around in the evenings. The procession in Mérida was wonderful.
The spring flowers will greet you along the way too.
Buen camino
Edit: not a bad idea to get your Sevilla accommodation chosen due to the closeness to Easter / it’s a popular destination at any time of the year.