I never heard this referred to as "the abbey road reverb technique" - but using an EQ on reverb (and delays) is a very common technique to stop them muddying up a mix
I would actually experiment with putting the EQ AFTER the reverb on your reverb send bus - this means you can simply send all your tracks to the bus and then "sculpt" the overall reverb sound with EQ
Many reverbs actually include high pass filters within the plugins so you can achieve the same thing when using them as an insert a effect