Firstly I don't follow any social media news because I'm not on social media. Secondly, just last week in a press conference - not some social media post - Julius laid out his discussions with the ANC and what he required. You're living in lalaland if you think that the DA's hard public stance on this agreement cannot upset the apple cart. There are many in the ANC, at this very moment, who would happily see the ANC partner with the EFF instead.
As for Julius losing his support base... In that very same press conference he alluded to being aware that this may be the natural death of his party.
Other than that, there seems to be this idea around here that the DA can call shots because the ANC need them when the opposite is actually true. The DA need the ANC and will have to play nice in order to keep the EFF out.
The IFP guy, Hlabisa, is trying to mend these fences now but he is in it for himself too because a DA withdrawal leaves KZN hung.