Can they announce that I am no longer an U.P if I start saying things in front of JW's?
Depends on what you "start saying," dear XPX (peace to you!). If it doesn't go along with their teachings... regardless of whether it's the truth... regardless of whether it's "in the Bible"... including their Bible... then yes, most certainly, they can... and will... make such an announcement (well, they'll whisper it to others, first, and then if you don't change... and/or don't stop participating in FS... they will announce that you are no longer a UP in order to keep anyone from "working" with you "in FS").
As for being accused of apostasy even though you are not baptized... they absolutely will make that accusation. Heck, they'll make it even if you're NOT an apostate, simply if you deviate from their teachings. They would... because THAT would be the REASON they would give to "remove" you as a UP. Your "apostasy"... from their teachings. (Which was absolutely STUPID in my case, as the only deviation I made... at the time... was:
(1) That Judas WAS at the last meal that my Lord shared with his disciples... and both Luke and John corroborate this - but "the Society" doesn't teach it, so I was "running ahead of the things written ['in the Watchtower']"; and
(2) That one does not have to be "elderly" to be called, chosen, anointed, or partake... which is corroborated by the fact that practically everyone (at least, those of significance) recorded in the Bible as being called, chosen, anointed, and/or partaking... WAS A YOUNG ADULT IF NOT A CHILD AT THE TIME:
(a) Moses (hidden at birth);
(b) Samuel (called at age 5);
(c) Daniel (chosen around age 17);
(d) Jeremiah ("a boy");
(e) Christ (in his Father's "house" at age 12)...
(3) If not no more than age 30:
(a) The original 12 Apostles (all of who were contemporaries with my Lord); and
(b) Christ (baptized... received holy spirit... instituted the evening meal... and poured out holy spirit... all at age 30)...
(4) Or not even born, yet:
(a) Cyrus (called "my anointed" by God before he was even conceived, let alone born);
(b) David (whose was seen by the Most Holy One of Israel when just an embryo and anointed when a very young man);
(c) Jeremiah (a boy when called, not even formed when known by the Most Holy One of Israel, and chosen when anointed with holy spirit);
(d) John the Baptist (prophesied before he was born and anointed in the womb); and
(e) Christ... millenia before he was born in the flesh...
Dear one, they don't care who... or what... you are. Simply disagree... or teach/say something different than what they teach... and you are an "apostate," as far as their "wolves" are concerned.
I bid you peace.
A slave of Christ,