There are many perspectives from which to answer your question "Does it make any difference if I just GET or POST here?" In short, YES it makes a difference.
GET and POST are both susceptible to CSRF attacks. By using a GET you are creating a wider attack surface. For example an IMG tag in an email could run your DELETE api on an unsuspecting user. Using a POST makes it less trivial. You'd be better off using post without supporting anti-forgery than by using GET. Ideally, you're using POST with anti-forgery tokens.
Other considerations can include:
- How the cache handles this request
- Adherence to REST principles (assuming you intend to have a "REST"ful/like design)
- It's usually assumed that a get doesn't directly manipulate server side state
- In theory a URL identifies the location of a resource, if you delete that resource with a get, what happens next time you call the get?
- A get won't be protected by CORS because it's assumed to not modify state, the browser will execute the GET and just not return the response to the offending site. With a POST the browser will run a CORS preflight check using the OPTIONS verb to make sure the request is allowed by the CORS policy returned by your server prior to your server receiving a request with the verb POST.