It happens, but doesn't happen to everyone immediately at some certain mileage. I have a build date 6/05 2005 v6, so a pretty late 05. Not sure when the 06 started production, but in 11/05 they did a redesign of the v6 HG. Anything build date 12/05 and after should be okay.
FWIW, 2005 v6 with 213k miles on original head gaskets, old design. I also drive it like I stole it sometimes because I'm an idiot lol. Coolant reservoir has dropped probably 2" since when I last filled it 12/19/19 and last oil analysis did show some traces of coolant in the oil, although it decreased from the first change I had analyzed. Decreased significantly enough that Blackstone Labs thought I had fixed the HG and these were just trace amounts left over. Lat analysis was something like 50ppm Potassium and 28ppm Sodium in oil. I took another sample when I changed it last week, so we'll see what the results are with this one.
And 03 to I believe early 04 v6 have the 4 speed. Late 04s and all 05s should have the 5 speed. All v8s have 5 speed.
This could be another helpful resource:
*** V6 Head Gasket Action Request ***