If he's not posting GPS recordings, it sounds fake. EDIT-- maybe not: see below.
But there are a few riders going for the 75,000 miles in a year record. See this thread: UMCA announces a new record category: highest annual mileage. Like I posted in that thread, it's like riding a continuous 1200km Paris-Brest-Paris ride for a year.
See UK cyclist Steven Abraham's web site oneyeartimetrial.org.uk He's basically spending all his waking hours riding, with a support crew and donated places to stay each night. Jan 25: at 4651 miles.
From his website:
Steve is backed by a team of volunteers who organise everything from sponsorship and donations to providing food, accommodation and maintenance each night.
This is an expensive undertaking just in terms of equipment. All Steve's food and living expenses also need to be paid for during his year away from work.
Here's another rider from the USA, Kurt Searvogel. His Strava page shows 3263 miles.
Strava says there are 3 official riders:
The two above and
William "Ironox" Pruett. -- his strava page shows 800 miles in January. Perhaps he started in mid-month?
Strava has a "club" for these riders, with 122 members, most going for their own personal record, I suppose.
Strava Highest Annual Mileage Record club.
Here's the Ontario guy. It looks like he's in Florida right now.
Profile for OHHD
Browsing his history, he rides 80-150 miles just about every day. The site's weekly or monthly charts are in km, not miles. His summer 5500 km months are 3400 miles. As of Jan 25: 2478 miles, 99 miles a day.
It sounds possible, but GPS recordings would be useful for a sort of proof.