On whatever car he'* talking about, he may be right.
I've been preaching about laminar airflow for some time now. Read the airbox mod article in Techinfo. With a stock airbox, leave it in. I agree that far. But with a custom intake, and the laminar flow it provides, you CAN safely remove the screen for less restriction. I have yet to see a failed MAF sensor caused by this, and until I do, I'll continue to say that this is a 'safe' mod. From my own personal experience.
The lean condition he talks about doesn't apply to my car, at least. I have an Actron scantool. My MAF and O2 sensor functions are unaffected and unharmed. My A/F ratio is perfect.
This makes the ECM lean out the fuel mixture and add timing. Then the oxygen sensors read the lean fuel mixture and bump it back up to compensate for the MAF sensors low readings.
This is not the case on my car at all. My A/F ratio and timing are normal. The PCM can adapt to these minor changes.