Say I own "throw0101a.com", and then use "dev.throw0101a.com" and "prod.throw0101a.com". (Or you own CydeWeys.com.)
Previously, when .dev and .prod were not TLDs, it was fairly safe to type "ssh websrv01.dev" and "ssh dbsrv02.prod" because if the queries leaked onto the Internet they'd fail.
Now, with the post-Google TLD changes, if you type one of those things, and the local DNS happens to not be configured properly (i.e., the resolve.conf 'search' options is not present), then strange things can happen.
Further, if you put "websrv01.dev" in a browser now, it may go off into the Internet and try to be clever about auto-complete instead of just doing a local query.
Relying on DNS search lists to find the right host is a bad security practice that has caused security incidents even outside the context of the creation of new TLDs. It's best to always use fully-qualified domain names. A lot of people responsible for implementing DNS search lists in the first place now regret having ever created them.
More info at https://www.icann.org/en/system/files/files/sac-064-en.pdf (particularly section 4.1.3 and the preceding logic leading up to it).
See https://jdebp.eu/FGA/dns-use-domain-names-that-you-own.html for more explanation.