Just because Republicans haven't found anything incriminating after years of searching doesn't mean they're going give up their search for something -- anything -- to justify their own existence.
Oversight Committee Chairman Jason Chaffetz (R-UT) says just because the election is over doesn't mean they're done fucking that chicken.
“This was never a political targeting from the beginning. Just because there’s a political election doesn’t mean it goes away. So of course I’m going to continue to pursue that,” Chaffetz said. [...]
“It’s potentially one of the largest breaches of security in the history of the State Department. It cannot and should never be repeated again. How was it that so much information was able to migrate out the door? These are still open questions that we need to finish up so they don’t happen again.”
No, Chaffetz isn't referring to Russian or third party hacks, he's referring to former Secretary of State Hillary Clinton's email server which was never breached. No information "migrated out the door."
The reason Republicans intend to continue investigating this should be obvious. Spending their time investigating a political opponent who they've already investigated ad nauseum will excuse them from investigating something real. Letting go of the email nontroversy would mean moving on to other things and, as far as they're concerned, there is nothing else worth investigating.
Don't be surprised if Trump's eventual secretary of state, whoever it may be, uses a personal email account. Don't be surprised if Trump's entire administration communicates off the book. Don't be surprised if congressional Republicans don't give a single shit about it.