These certification documents from the National Communications Commission of Taiwan indicate the Google Pixel 3 and Pixel 3 XL will indeed have wireless charging:

The documents also indicate some of the manufacturer details of the accessories:

Charger (TC G1000-US) manufactured by Flexronics or Phihong

Lithium Battery (G013A-B / G013C-B) manufactured by Desay or Sunwoda

USB Cable (G016C) manufactured by LOTES, Foxlink or Luxshare-ITC

Furthermore, the documents also confirm the Pixel 3 will be compatible with LTE Bands 1, 3, 7, 8, 28, 38, and 41, though the FCC Filings indicate a separate set of LTE bands so there is either a different model approved for Taiwan (bearing the same model number) or there is software on the pixel that sets the LTE bands based on the country you are in.

Source Documents:

NCC-Google-Pixel-3 NCC-Google-Pixel-3-XL

Please hotlink the documents or this article if you reference this material.