Why riot dont care about the "preseason-Phase"

Imma just wondering about the Patchnotes. After 9.2 i´m a bit asking myself why riot didnt do those balance-changes on Preseason. all patchnotes released on preseason this year were complete serious. nearly every main problem was ignored the whole preseason (due to nexus blitz? i rly cant explain it) and since the start of new season riot thinking lets change everything and fck the whole crowd or something. I have rly no problems when riot keep holding league actual but Changes like the 9.2 Patches or the actually planned 9.3 PBE changes are blowin my mind. Patches like this and something the most ppl waited for (hello adc mains) are the perfect thing to release on Preseason for testing and keep balance it in the upfollow patch. Now its gonna break the game like Sion charging into 5 enemies .

Feels a bit weird that riot wont take care about preseason and just wanna fdestroy my early season with some changes -.-