No way. The manga portrays their connection through mutual respect and competition in their journey to become great heroes. A kiss is not part of that narrative at all.
Another theme is growth. Both characters grow as heroes and as individuals. In these fanfics, you can see how they influence each other's development, whether it's in terms of their quirk usage or their mental strength. For example, Deku might inspire Bakugo to be more selfless in battle, and Bakugo might push Deku to be more assertive.
Another theme could be growth. Deku is constantly growing as a character. In these fan fictions, his relationship with Bakugo's mom might contribute to his emotional or personal growth. Maybe she offers him advice or support that he doesn't get from other characters. And also, there could be themes of unexpected relationships. It's an unusual pairing, so exploring how such a relationship forms and what it means for the characters involved is likely to be a theme.