I think that is about right. Very short, no leading toward, r expectation of a response. I can see why you would be a bit worried that it is pursuit like, but it doesn't feel like it to me. Pursuing is contact for no reason, that asks about him, tells about you, and expects a response. All you did here was complete an existing transaction. My view is that even in the worst situation we should still be able to say thank you.
