I was able to replicate the above on an AT and Simple site.
The link to work.
It breaks the block.
Safari Version 12.1 (13607.1.40.1.5)
OS X 10.13.6

This is what it shows in the Console:

2017169-zen
Verified on Simple/Atomic but not in Gutenberg nightly.
It's more specifically breaking on window.getSelection().getRangeAt(0)

Which I think lines up with https://github.com/WordPress/gutenberg/blob/4108e37d3771b5871cd720216432b5bbd5255551/packages/format-library/src/link/inline.js#L82
Update: I can reproduce this in Gutenberg master with the following steps:
In Safari:

D28094-code has a temporary fix for WP.com sites while we wait for changes from https://github.com/WordPress/gutenberg/pull/15576
Fixed by D28094-code.
Created https://github.com/Automattic/wp-calypso/issues/33004 as a reminder to revert D28094-code during the next Gutenberg update in WP.com sites.
Most helpful comment
D28094-code has a temporary fix for WP.com sites while we wait for changes from https://github.com/WordPress/gutenberg/pull/15576