Yes, it is very much possible to swap a pixi sprite's texture with gsap.
I was able to swap the texture of a sprite with a canvas this way:
const dataUrl = canvas.toDataURL('png');
const base = new PIXI.BaseTexture(dataUrl);
const newTexture = new PIXI.Texture(base);
gsap.set(resource, {
pixi: { texture: newTexture}
});