It is significant to note that the teaching of "sight" words was not one of the "persistent questions on beginning reading" which a carefully- selected group of experts recently chose to discuss (1). Indeed, from what one knows of this topic it would have been surprising to find the notion that young children should be first taught words as "wholes" being given critical examination in any such discussion. This is because the validity of instruction in "sight" words is accepted without question by almost all of today's experts in reading instruction.
Groff, P. (1975). The Mythology of Reading: I--Sight Words. Reading Horizons: A Journal of Literacy and Language Arts, 15 (4). Retrieved from https://scholarworks.wmich.edu/reading_horizons/vol15/iss4/4