It is true that 道 (dao) can mean to say, speak, talk.
https://www.mdbg.net/chinese/dictionary?page=worddict&wdrst=0&wdqb=%E9%81%93%E5%8F%AF%E9%81%93
But I do not think this is the meaning of 道 in 道可道, (Dao ke dao), I think it only means the way or path, that we are on the path (Dao) to...