They would not be affected by the bot edit since such the phone tag would contain other characters, e.g. +1-555-555-5555 x123 or +1-555-555-5555 ext. 123.
Ref:
The value in the phone tag consists of only digits, spaces, parentheses, dashes, hyphens, periods or invisible formatting marks such as non-breaking spaces, zero-width spaces
If there is anything else, like letters, then the object is not considered for automatic editing.
The website considers either of those formats above as valid and suggests fixing anything else, like +1-555-555-5555 extension 123 to +1-555-555-5555 x123