Just put the width and height in a separate animation.
var scaleIt = gsap.timeline({paused: true,reversed: true})
.to(viewBox, {
motionPath: {
path: [
{ x: 100, y: 220, },
]
},
duration: 1, ease: "none"
})
.to(viewBox, {
ease: "none",
duration: 1,
width: 500,
height: 200
}, 0)