Its no news Miui 10 Global Beta Public was release for All in OTA 14 June 2018 and rom was 8.6.14
For this phones
Mi 6, Mi MIX 2, Redmi S2, Redmi Note 5 Pro/Redmi Note 5 and Mi MIX 2S.
http://en.miui.com/thread-2883296-1-1.html
Miui 10 Global Public beta faster release than China Miui 10 Developer Public for some devices.
Miui 10 China dev Public was release 19 june 2018 and it was rom 8.6.19
http://en.miui.com/thread-2927450-1-1.html
For phones
Mi 8, Mi 8SE, Mi 6, Mi 5, Mi MIX 2S, Mi MIX 2, Mi MIX, Mi Note 2, Redmi S2 and Redmi Note 5.
Global MIUI 9 8.6.21(its build from tommorow in close beta) will be relase Public 22 june 2018!
Public are allways Friday, but rom is from thusday.
http://en.miui.com/thread-2929506-1-1.html
But its not STABLE Miui 10!, Its Developer((Beta)) rom of Miui 9.
Please read only official annoucment on miui.com and en.miui.com not from fake list anothers sites.
They release Miui 9 for all phone to fix bugs.