I don't believe Netflix or Amazon carry any live broadcast material so don't require a TV license, not sure how that works under the changes to "catch up" legality where they have BBC shows, etc. but as you pay for those via those services I suspect they are licensed differently to the same thing on iPlayer, etc. though that point seems very vague - one of my relatives is having a melt down at the moment as they don't own a TV or watch any live TV but do sometimes buy BBC shows via Amazon, etc. and just had the leaflet through about catch up changes which isn't clear on that point, but a bit threatening in tone, and no one at the BBC has given them a straight answer when they called them.
There is no change, except for using iPlayer.
Non of that requires a license, its rather simple.
Are you watching or recording something that is also being broadcast live on conventional TV channlea, free view, sky, virgin or from September using iPlayer, if not, no license required. So you cab still use catch up of on other channels like 4od with no issues, as long as its not the live chabbels.