Boyd states that
"it is well established that, in 2016, the U.S. government and others undertook certain intelligence-gathering and investigative steps directed at persons associated with the Trump Campaign ... there remain open questions relating to the origins of this counter-intelligence investigation and the U.S. and foreign intelligence activities that took place prior to and during that investigation.”
Boyd goes on to note activities that have been undertaken thus far, mostly to coordinate with other agencies:
1. Preserve relevant records,
2. Ensure the availability of witnesses,
3. Identify and assemble relevant materials.
For my money, however, the key is in the first paragraph. Boyd makes no bones about how broad the scope of the "review" is. The review includes not only the actions of the US intelligence services, it will also seek to illuminate the role of foreign intelligence services as well as non-governmental organizations and individuals:
The Review is broad in scope and multifaced, and is intended to illuminate open questions regarding the activities of U.S. and foreign intelligence services as well as non-governmental organizations and individuals.
The US intel agencies may include not only the FBI and CIA but possibly the DIA (contacts with Papadopoulos in London). The sky's the limit as regards the foreign intel services--Brits, of course, but probably Aussies, Estonians, maybe Italians. The list could well be longer. Individuals and non-governmental organizations? Chris Steele, FBI/CIA/Other informants such as Halper, Mifsud, Downer. Fusion GPS, along with principals such as Glenn Simpson, Mary Jacoby, and Nellie Ohr--plus the DNC lawyers Michael Sussman and Marc Elias. No doubt White House officials fall within this broad scope, as well.
The bottom line is that this looks like the real thing. An additional indication of how big it is may be that "existing office space" has been turned over to Durham and his team. I'd have preferred to hear about "additional" office space being rented for the purpose, but we'll have to give it time.