I will repeat this information since my initial reaction to this news was, like yours, one of caution. Given the conference he played in, the Mountain West Conference, Gleeson almost certainly played one of the highest per-game altitude schedules in the country. Here are the elevations (roughly) of the stadiums he played in last year. Some figures are cited specifically for the stadium, while others represent "university" elevations.
University of Wyoming (War Memorial Stadium: 7,220ft.)
University of Texas (Darrell K Royal Texas Memorial Stadium: ca. 500 ft.)
University of Idaho (William H. Kibbie-ASUI Activity Center, more commonly known as the Kibbie Dome: 2,610 ft.)
University of Nevada (Mackay Stadium: 4,564 ft.)
Fresno State University (Bulldog Stadium: 338 ft.)
University of New Mexico (University Stadium: 5,174 ft.)
UNLV (Sam Boyd Stadium: 1,600 ft.)
If you check his per-game stats (see p. 7 of
http://grfx.cstv.com/photos/schools/wyo/sports/m-footbl/auto_pdf/2012-13/stats/season_stats.pdf), as a reflection of team per-game punting stats (taking into account that he was responsible for all but one punt), he had two subpar games, one against Texas on the road (37.6 ave.) and the last game of the season at home vs. San Diego State (35.2 ave.). According to this webpage (
San Diego State 42, Wyoming 28 - San Diego State University Official Athletic Site), the wind was blowing from the west at 28 mph during the latter game, which detrimentally affected both punters.
What does all of this data mean? Hopefully nothing significant but it does have to be taken into consideration in projecting how well his performance will translate at Knoxville's altitude and humidity.
Texas and Fresno State most closely approximate conditions in Neyland and two interesting stats emerge from those games. First of all, if you combine the stats for those two games, you come out with almost exactly a 40-yd. average (15 for 598 yds.), which, on the surface, does not sound like too much of a drop off coming down from 7,200 ft. Against Texas, however, he shanked his first two punts, 19- and 20-yd. efforts, respectively, and then proceeded to nail his other three punts for 149 yds (49.67 ave), which included two punts over 50 yds., one of which was good for 54 yards. And those punts were launched in Knoxville-like climatic conditions in what was his first collegiate performance ever and in a hostile environment to boot. Considering how many times we have watched Palardy and Darr unravel following a bad kick or two, that level of composure for a first-game freshman is most impressive.
Finally, it is not unrealistic to expect his overall leg strength to increase somewhat over the course of his career.