Her rhetoric might change in the general, but I don't see why that possibility would be made more likely by a position that she's open and up front about during the primaries. Maybe if she were refusing to answer questions about how she will fundraise in the general, but she's answered the questions, so there's nothing about it that hints that she will be pulling surprises in the general.
Personally, I hope the D nominee does whatever it takes within the law to beat Trump, so I'm happy about this position. To me, the primary is a completely different situation than the general. The primary is about picking the best Democrat. The general is about beating Trump with whichever Democrat is the nominee, even if it is a shitty Democrat like Biden and there is a better, totally pure third party candidate available. Foregoing the donor class in the primary serves that end, and so does playing the money game in the general.
But I can understand if you think fundraising method is a matter of uncompromisable principle. I don't — I think we should drastically change what money can do in the general, but not tie our hands before the laws are changed, giving Republicans a huge advantage.