I am asking about milestones, if any are publicly stated or recognized.
~ 7.X - 8 versions were preceded by many daily commits.
:version
VIM - Vi IMproved 8.0 (2016 Sep 12, compiled Jan 6 2018 23:48:57)
Included patches: 1-1428
Compiled by renato@xps
Huge version without GUI. Features included (+) or not (-):
+acl +cmdline_hist +eval +job +mouse +num64 +scrollbind +termresponse +windows
+arabic +cmdline_info +ex_extra +jumplist -mouseshape +packages +signs +textobjects +writebackup
+autocmd +comments +extra_search +keymap +mouse_dec +path_extra +smartindent +timers +X11
-autoservername +conceal +farsi +lambda -mouse_gpm -perl +startuptime +title +xfontset
-balloon_eval +cryptv +file_in_path +langmap -mouse_jsbterm +persistent_undo +statusline -toolbar -xim
+balloon_eval_term +cscope +find_in_path +libcall +mouse_netterm +postscript -sun_workshop +user_commands -xpm
-browse +cursorbind +float +linebreak +mouse_sgr +printer +syntax +vertsplit +xsmp_interact
++builtin_terms +cursorshape +folding +lispindent -mouse_sysmouse +profile +tag_binary +virtualedit +xterm_clipboard
+byte_offset +dialog_con -footer +listcmds +mouse_urxvt +python/dyn +tag_old_static +visual -xterm_save
+channel +diff +fork() +localmap +mouse_xterm +python3/dyn -tag_any_white +visualextra
+cindent +digraphs +gettext -lua +multi_byte +quickfix -tcl +viminfo
+clientserver -dnd -hangul_input +menu +multi_lang +reltime +termguicolors +vreplace
+clipboard -ebcdic +iconv +mksession -mzscheme +rightleft +terminal +wildignore
+cmdline_compl +emacs_tags +insert_expand +modify_fname +netbeans_intg -ruby +terminfo +wildmenu
system vimrc file: "$VIM/vimrc"
user vimrc file: "$HOME/.vimrc"
2nd user vimrc file: "~/.vim/vimrc"
user exrc file: "$HOME/.exrc"
defaults file: "$VIMRUNTIME/defaults.vim"
fall-back for $VIM: "/usr/local/share/vim"
Compilation: gcc -c -I. -Iproto -DHAVE_CONFIG_H -g -O2 -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=1
Linking: gcc -L/usr/local/lib -Wl,--as-needed -o vim -lSM -lICE -lXt -lX11 -lXdmcp -lSM -lICE -lm -ltinfo -lnsl -ldl