Noticed this too in low elos (gold/plat) basically everyone got "boosted" by a tier (previous golds are now plats, silvers are now gold, etc.) which is more noticeable in lower population servers (for ex. ph server which currently has less than 200k recorded ranked players as per op.gg)
.
The trend has almost always been:
top 2% - diamond
top 10% - platinum
top 30%~ - gold
top 50%~ - silver
.
Now it's:
top 1% - master above
top 10% - diamond
top 30% - platinum
top 50%-60% - gold
.
I think this might be because of deteriorating number of players and ranked play time, which basically makes playing ranked right now super shitty because (somewhat) more "unfair" or unbalanced matches coupled with low # of games players.