https://wccftech.com/final-fantasy-vii-remake-summon-mechanics/

Final Fantasy VII Remake will feature the Summon mechanic that has become a staple of the series since the third entry in the series, but it seems like it will work differently than in past titles.

In a video recently shared on Twitter, Final Fantasy VII Remake producer Yoshinori Kitase confirmed that summons will be available only during boss battles and against strong enemies, likely mini-bosses. Summon materias will still have to be equipped, and they can only be used only once the materia starts resonating, so there are still some conditions that have yet to be detailed.