You haven't at all backed up the assertion that the BBC are "under _specific_ instructions...to drop impartiality and implement a social justice agenda" (emphasis mine). You provided evidence that the regulator has demanded that they hire and air a more representative mix of gender, ethnic background etc.

Nowhere above has OFCOM directed the BBC to air different opinions. Regarding the Today programme example: Deliberately featuring a female (rather than male) climate science expert after featuring a male vaccination expert is entirely orthogonal to impartiality.

[EDIT:] I'm not specifically arguing that the BBC has no bias. I'm saying you haven't demonstrated that OFCOM have demanded a bias.