In my experiences, a lot of edit summaries already are "canned", the field is left blank and is populated by an automated summary about a section. And that didnt break the internet.
There are 3 existing types of automated elements in edit summaries:
1) If you click [edit] on a section heading (rather than for the whole page), it will automatically insert this in the wikimarkup-mode edit-summary text-area:
/* section title */ which transforms into this in watchlists/RecentChanges/etc: (→section title: )
2) the 4 types of fully automatic editsummary (list here), eg. (←Blanked the page)
3) the "Tags" that gets appended after the edit-summary, eg. (Tag: VisualEditor)