theres a difference between undecided and unannounced.
based on progressions speed of the community we already decided both on the date of opening loa and the sieges about 2 weeks ago, its just not announced cuz every announce of the future tends to have impact on the actual state of the server somehow,
would also like to point out that at this moment over 90% of the population is still under lvl 64. yes i know some people play faster, others play slower but for us we need to keep a balance on the possibility of the gap between top groups and people who play a bit less or a bit less efficient, thats the whole point why the lvl cap (avoid level gap) and loa not open from start (avoid gear gap) were implemented on first place.
on TI you fought dragon valley for 5 months untill 1.3 and only 1 month after this you had loa being opened. we will not keep the same 5+ month time frame as we understand 1.5 progress is different from 1.0/1.3 progress but we also not gonna cramp 6 months progress into 1 month time frame, all i can say is following the normal progress speed that players are having loa should be open somewhere near early mid of next month but you gotta wait on official announce for specifics with dates.
about sieges, you and i might be remembering different sieges, cuz from what i can remember on the first sieges we had on TI was everyone getting rekt by the guards and complaining how strong mobs are, so i'd say giving the players a bit more time to prepare before it comes in handy for everyone.