I remembered a story from some time ago that played with the fact that Spike was somewhat different to other dragons and what would happen if another dragon like him turned up: https://www.fimfiction.net/story/143810/ten-years-gone
It even inspired more stories and a group, though an even greater number playing around with the idea would have been better:
https://www.fimfiction.net/group/213579/ten-years-gone