I would be concerned about the engine jumping time and causing contact between the intake valves and the pistons.
Thanks for the reply I have had the car for 3 years always did my oil change changed my plugs about every 4 months and it just passed smog here in Cali in February. Thank you for the advice well takenThose finger roller followers and stationary hydraulic lash adjusters should never go bad/fail. There is not that much stress on them from the valve spring or action of the VVT. I've never seen this failure on durability engines ran at GM in the past. Almost makes me wonder if it might be a manufacturing spill. Something created a nasty stress riser or its a material issue. Of course being this old, gm will not care to even look at the parts. Eaton made these back in the day, as I recall. They were not made inhouse by gm. Sorry this happened to you, and you may never know why. I do know they are not unique to exh or intake, they are all the same part number. Why only intakes failed....good question. How many miles on your car and do you use good quality full synthetic oil?? You should be able to cycle the motor over by hand with the valve cover off to witness valve train action and any type of anomaly with the valves/springs.
I agree, but there is an internal mechanical stop in the cam phaser to prevent this from happening. If the phaser solenoid went into some sort of dithering mode?...but the OP said he was at idle. If the SHLA seat is too shallow it would permit this failure mode. If this occurs due to incorrect machining (it happens) the 'lash' in the lifter will bottom out making a 'solid lifter' and thus create a hard stop at max cam lift. Not a good scenario. I personally reworked 1200 engines at Flint Engine South, the 4.2 L inline six due to this exact issue. A set up person could not do basic math during a tool change and went shallow on the SHLA seat. Cold Motoring Test caught the condition.....If it did not jump time on the chain , I would suspect a problem with the cam/phaser changing the cam timing to far . It's really hard to think all 8 intakes failed from manufacture problem ( problem with the rockers) . Impossible odds for them all to fail unless there is a mechanical fail .