Cheaters are an inevitability in any multiplayer game whether free to play or not. Their is no real full proof way to ensure that cheating will never happen simply due to the nature of the arms race between cheating and anti-cheat detection technology both improving to counter one another. As people have mentioned before, 343 going back on free to play would look really bad on them pr wise and we'll just have to hope that infinite will have a decent anti-cheat as well as a good reporting system when hackers do show up.They don't have a population now so of course they would want everyone free to play. Their last 2 games were flops
Considering how long Halo 5 lasted without totally blacking out (Only a few 'mildly unpopular' game modes/lists ever really reached a critical state)
and still gets large amounts of people asking "But what about Steam?" years later.... I think 5 is more a "Mixed bag - love it or hate it" than a genuine 'Flop' - not trying to change any minds here of course, but from my experience 5 was more a mixed bag. (Not that I didn't enjoy Dominion in 4 mind you.....)
Back on-topic, there's no way in the world that 343's going to change FTP at this stage in development, let alone over something that'd be an issue regardless.