Death Note - Box 1 (Episodios 1 A 20) - Edición Coleccionista [Blu-ray], as the box set is entitled, apparently covers only the first twenty episodes of the anime. Presumably Box 2 will finish off with the remaining seventeen.
Selecta Visión - the anime's distributors in Spain - hinted at the fact to fans during their recent tenure at Japan Weekend (Selecta Visión Confirma Las Licencias de Death Note y Assassination Classroom, report by Víctor González Valle, Region PlayStation (Feb 14th 2016)).
However there's been no official announcement as yet, beyond vague references via Twitter.
Like that on March 24th, when a fan asked if Selecta Visión would make available a Catalán version of the Death Note anime, someone from the company responded that the new Blu-Ray edition would be in Catalán.
Though representatives at the convention suggested that it would appear in May, retailers across the board have since attached a release date of July 6th 2016. Moreover, their attendant information uniformly names the language as being Español, not Catalán, for this Blu-Ray Spanish Death Note dub.
Beyond that, all that we know is that Death Note Edición Coleccionista will be spread over four discs with a total running time of 500 minutes. No word on any special features, additions nor even cover art as yet. We'll keep you posted as soon as we know anything else at all.
See Blu-Ray Death Note - Box 1 (Episodios 1 A 20) - Edición Coleccionista on Amazon Spain.