It's even more natural a progression since the exact same main characters were already in place from the prior film. Sam did want Vulture and the Sony execs wanted him to turn the character into a sexy female character. Just one of their "creative differences" that lead to them parting ways.
TASM plot with Lizard still could've happened and imo been a better story. We wasted an hour on an inferior origin and swooning over Gwen. Details, again, already nailed down from Spider-man 3. So much more about Connors family, Oscorp, Lizard transformation etc could've been explored. Things this film omitted and/or didn't really get into very well.