Ok then.
I see you can get these modules without the ceramic doo dah, if I can get those that'd be best methinks.
The smd probably was a choke, the schem shows a lpf with 2 chokes with the ceramic antenna.
I wondered if the ceramic doofer worked as a tuned filter part of the input, and yes I see permitivity and other stuff in coax affects the speed of signal travel, ie slows it down, so it makes sense to do that with an ant to reduce size.
The data sheet depicts the chip has a 50 ohm input inpedance at wifi freq's, so its a good candidate for a home bodged yagi or co-phaser.
I'm not sure how low in sig strength esp8266 01's go, but I've just been doing some tests and got a long way off through metal structures & walls, and the device was still working at -88dB, not bad for a pcb ant.