Assume that in this culture that everyone can read minds and project images into the minds of others. Can there be a way for such a culture to evolve speech?
I assume you by "telepathy" do not mean "mind reading". Broadcasting your message to everybody in proximity has some disadvantages. Perhaps you do not want everybody to hear it? Or want to have control over the information? Then you must have a more secure way of communication. That is a so strong motivation that I predict development of a language would appear anyway.
That is, if you do not count the transfer protocol and encoding of the telepathic message as a language. From a theoretical linguistic point of view, that is a language too.