Has Boko Haram pledged allegiance to Daesh?
Yes, Boko Haram pledged Bay'ah to Daesh many years ago and that Bay'ah remains in effect. In practice that probably means that Daesh sends some combat enablers to Boko Haram (trainers, embedded advisors, logistics [supply, transportation, maintenance], ISR and C2. But probably not a lot. Or the Boko Haram wing of Daesh would have demonstrated greater success against the Nigerian, Niger, Camaroon and Chadian armies and police.
But perhaps the goal is to keep a logistical and organizational hub in the region that can be reinforced at a later date at a time of their choosing. In which case from Daesh's point of view, Boko Haram is doing so so.
Still Daesh doing even this much has led to a semi permanent US FID base in Nigeria that trains the Nigerian Air Force, a FID mission to Ghana and to other countries in the region. And assistance to the region from many other countries.
Thank goodness Biden Pres has not yet withdrawn troops from the region.