This is generally answerable considering the probability of winning given the coin toss; I haven't seen anyone modelling specifically the chance of taking the opening kick for a TD. That's because that is not the only factor at hand in the overtime consideration; a proper evaluation needs to consider the entirety of the outcomes of overtime in order to evaluate whether it favors the receiving team.
As of late 2015, the receiving team had won slightly more than half of the time (50.7%) since the new overtime rules (allowing a drive after a made FG - it used to be even a made FG ended the overtime). ESPN estimated a 53.8% chance overall (likely higher than observed when you control for the already-extant likelihoods, specifically the better team being already more likely to win).
In 2014, in a blog post at the Harvard Sports Analysis Collective, an analysis was done to determine the odds of winning an overtime game based on a Markov chain analysis. Among other things, it noted that a drive from a kickoff ends in a touchdown about 20% of the time; this was before the adjustment to the touchback distance, though, so I would not necessarily take this as correct for 2016 and beyond. I'm also skeptical that you can consider an early game drive similarly to a late game drive or OT; a lot of information has changed hands by that point, leading both sides to have some opportunities to improve - but perhaps one more than the other; and further, defenses are tired (and while both sides may be tired, it seems to hurt defenses more than offenses overall).
If you want to look solely at the outcomes, well, there have been fewer than 100 overtime games since 2012, so it shouldn't be too hard to just count them?
