Can genes that activate transcription factors also called be called transcription factors? If the sole known function of a gene is to activate a transcription factor, would that gene also be considered a transcription factor, or is there a word for such genes that are further upstream on the transcription activation cascade?

Yes. For an example, see this list of targets of NF-kB (a transcription factor). Many other transcription factors are included there. As for a TF that does _nothing_ except activate another, _single_ TF? I don't know that those exist - TFs tend to modulate multiple genes.