The only misleading aspect of the headline is that the scheme is being funded by the NHS. Strictly speaking the NHS has no money. It only has what is allocated to it from the sums extracted from taxpayers. So it is taxpayers who are funding this scheme.
Other than that there is nothing misleading about the banner. The new scheme is known as a sperm bank and there does not seem to be any dispute that the it will be used by lesbians. The headline does not say it will be "exclusively" for lesbians and since estimates indicate that around 25% of its "customers" will be lesbians I see nothing misleading about it at all.
Just for the record and so as there is no misunderstanding I do not believe such a scheme should be funded by the taxpayer for anybody, gay, straight, sick, poor, rich, black, white, or anybody else. This is because I believe the world in general and the UK in particular needs to consider means of reducing its population and should not indulge itself in schemes designed to create children. There are more than enough of them around without trying.