(You could have provided links for the mentioned use cases.)
I looked at some of the use cases and I only saw guards. There can be many guards in a single else clause, which the proposed syntax could not handle.
for loop:
for loop:
if cond:
break
else:
if not guard:
code
# continue
if not guard_2:
code
continue
code
The situation is that the usage of these else clauses is very limited. I haven’t encountered them in practice, and if I do, I often have to refer to Python documentation. Then, I add comments like # no break or # no exception, which disrupts the flow of code reading. I am opposed to the else clause, and elif wouldn’t improve it.