The problem is that there is a huge skill gap between regular bronze and silver. 90% of active pvp player base are sitting on bronze. Solo 4v4 should be adjusted more to spread people around ranks. No point we have 5 ranks if 90% is bronze. +25/-25 should be fine for gold rank but for bronze it should be like +25/-10 and +25/-15 for silver.
I dont know why they change points needed for next rank but in fact there is problem with win/loose ration which should be adjusted for lower ranks not the points which player need to obtain.