Base M2 or M3 won't work either; a Thunderbolt dock cannot work around a lack of display pipes on the SoC. The M4 is the first base M-series chip that supports

Base M2 or M3 won't work either; a Thunderbolt dock cannot work around a lack of display pipes on the SoC. The M4 is the first base M-series chip that supports two external displays in addition to the internal display, hence the slightly different phrasing in your quote for the M4 generation.