Hjorimir
Adventurer
Nitpick: This is the second TPK and the third time they are making characters.
...and, no, I don't think it is a two-way street. There is no opposite to meta-gaming that the DM needs to be involved in. Real people make poor decisions all the time in real life; characters make poor decisions as well. (In my game I often say, "You all go to sleep?" Only to quickly be followed up by the players saying, "Nope! We set a watch order as follows..." They don't let me get away with anything. Oh how I miss the halcyon days of newbie players that I could torment at will.)
I don't think the DM should have to constantly remind players to be careful or use any particular strategy for two main reasons: it feels more like the DM is railroading characters and it isn't fun if the DM has to run the both the PCs and NPCs at the same time. One might as well just e-mail the players each week and let them know what cool things they did.

...and, no, I don't think it is a two-way street. There is no opposite to meta-gaming that the DM needs to be involved in. Real people make poor decisions all the time in real life; characters make poor decisions as well. (In my game I often say, "You all go to sleep?" Only to quickly be followed up by the players saying, "Nope! We set a watch order as follows..." They don't let me get away with anything. Oh how I miss the halcyon days of newbie players that I could torment at will.)
I don't think the DM should have to constantly remind players to be careful or use any particular strategy for two main reasons: it feels more like the DM is railroading characters and it isn't fun if the DM has to run the both the PCs and NPCs at the same time. One might as well just e-mail the players each week and let them know what cool things they did.