The question was brought up last night regarding cards and mission rules that gain threat and the timing of the Deploy/Reinforce step and the End of Round mission step. In particular, the card Imperial Informants triggered the discussion.
The Status Phase section of the Rules reference guide lists step 3 as Deploy and Reinforce and step 4 as End of Round Effects.
Imperial Informants reads "Keep this card secret. Play it at the end of a round during any mission. Increase threat by the threat level."
So, in keeping with the Status Phase order of operations, Imperial Informants should only be playable in step 4, at which point the additional threat cannot be used to deploy or reinforce until the following round (barring other special optional deployments as allowed by mission text). However, our Imperial player felt (and I agreed) that it goes against the "intent" of the card, which would seem to be a surprise reinforcement boost as it gives the Rebels a full round of warning that the threat is available.
We opted to play it in line with the RRG, but I wanted to throw this question to the forums and see if we missed something. In particular I'm interested in this interaction's greater reach, as it would also apply to any missions with end of round threat increases. In particular "Under Seige" comes to mind as it has lots of triggers for increasing threat at the end of a round.