Sony recently announced the FE 50mm f/1.2 GM, a spectacular lens that pushes the boundaries of the E mount. It seems they are not slowing down, as we will likely see three more lenses next week.
Nokishita has mentioned that Sony will likely be announcing three new lenses next week: the FE 24mm f/2.8 G, FE 40mm f/2.5 G, and FE 50mm f/2.5 G. While the new FE 50mm f/1.2 GM has shown itself to be a highly impressive lens, coming in at $2,000, it is very expensive, particularly for a 50mm lens, and for anyone who needs a 50mm lens but does not want to drop a lot of money, the 50mm f/2.5 G will likely be a much more affordable (and probably far more portable) option. Meanwhile, the FE 24mm f/2.8 G will likely offer a very affordable (and equally portable) wide option, suitable for walkaround work and many other applications. Lastly, the FE 40mm f/2.5 G should be an interesting lens. We have seen the 40mm lens emerge as an alternative between the more common 35mm and 50mm focal lengths in recent years, with many photographers applauding it as a refreshing change of pace.
Comparing to other huge 50mm lenses is the wrong comparison. 778g is 6x the weight of the ZA 35mm/2.8 which is probably the closest size comparison to what these lenses will be. 778g is 4x the weight of the current 50/1.8 and the 50/1.2 is approx 1.5x the width and length of the 50/1.8. The 50/2.5 will likely be significantly smaller and lighter than the 50/1.8. Pairing the new 50/2.5 lens with the A7C will likely be about half the weight of the 50/1.2 with an A7III (and probably be half the volume/dimensions too). So yes, these are intended to be more portable. They'll also be significantly lower profile for those who prefer that, and the 50/25 will likely be less than one quarter of the price of the 50/1.2.
If you’re looking for light weight, in the mid-late 70’s Nikon made a very sharp MF 50mm 1:1.2 that is only 400g. It is badass on the front of my a7Sii at night. One can be had on eBay for <$350.