There is no possible canonical answer.
For 2012 new gTLD round, each applicant was coming with some kind of business plan, for what it wants to do with the TLD. Some are restricted to a brand, some to a geography, some are bound by other restrictions, and some are completely open.
If you go to https://gtldresult.icann.org/applicationstatus/viewstatus and ...
TL;DR No one can predict the future (so theoretically the case you present can happen, in practice I wouldn't bet on it), especially because ICANN, in charge of TLDs creation has a lot of rules and procedures, that change over time, with decisions that can later be appealed, reversed, upheld, and redone. So expect the unexpected.
Now, in more details (the ...
In fact there are many more overlapping/redundant extensions. Consider for example the real estate TLDs:
.property .properties .realty .apartments .homes .condos .villas .mortgage .rent .rentals .house
plus the variants in foreign languages
.pics .pictures .picture
.photo .photos .photography
And maybe more in the future.
Yes, this is confusing. I ...