Not really. open this note: nostr:note16stm29mu3wpv9zu5psphv7nx54r89a028z0d9r5my3muljaml35sre4925
Discussion
When you have a Quoted kind 1 the image is not edge to edge. You would do the same for kind 1063.
That note has no images in it
It’s quoting this note which has images. Your change will still break images in damus and every other client, forcing it to use quoted posts to view images. 
But NIP94 is not a direct image. It is a quote event. I would expect to be rendered as such.
Here a post with a quoted image nostr: note1z3dt56fh42r85wf7tu6hq7fcecu9xpnj8kntxeg6zpps3j9gqhxqlh
Right note id nostr:note1z3dt56fh42r85wf7tu6hq7fcecu9xpnj8kntxeg6zpps3j9gqhxqlhhmp6
Having two different ways to display images is too confusing.
A much better and backwards compatible way could be done in either two ways:
1. nevent with internal kind and image url tlv. This would at least allow other clients to use the url if they don’t want to implement the attachment nip.
2. Keep the url and reference the metadata event id in a tag with a url index.
3. Probably many other ways that wouldn’t break anything.
If you really want this to be a file attachment instead of image then you could just keep the original upload method and let users know that clients might not be able to see your image if you use a file attachment.
All up to you, but damus will not be implementing this nip for image uploads, as stated before I think it’s simpler to encode this information into a completely optional small string so that its available on the post itself and so that clients can use the information to do all the hash checking stuff, but when they are ready, not forcing it on them.
Cheers,
Agreed. It could have been done in a backwards compatible way. NIP94 is just way too short.
Maybe in future, have a Q&A section within each NIP with regards to backwards compatibility and apriori event types?