As vidarh mentionned, you also have to take into accounts macros (carbs/fat/proteins split) and having to eat 3500kcal in 2 meals can be tough sometimes (in the weekend i often do a 6h or so).
I've eaten that way pretty much all my life so it was easy for me to adapt (it mainly consisted of more proteins and alternating more carbs on workout days/more fat on rest days).
That is, in fact, one of the more common forms of IF: one or two days a week, don't eat until the evening meal (and, depending on your specific practice, perhaps eat only lightly then).
If you usually have long enough between meals that skipping breakfast gives you a 16h period without any food, then sure.
When people do leangains they also do tend to focus on getting more protein etc. though, which can turn the 8h eating window into a big ordeal - I struggle to get the calories I need in two meals on Leangains due to the amount of protein I take; I keep wanting to skip the second meal because I'm still so full.
