Happy would be sad and confused. He doesn't like to see his friends in trouble. He would fly around trying to gather information from different guild members. He would also stay by Lucy's side, trying to cheer her up. And all of her other friends in Fairy Tail would at least have some doubts about the decision. They know Lucy's character, and her sudden expulsion would make them question whether the guild made the right choice.
Natsu would probably be very confused and sad at first. He's used to having Lucy around, and her sudden departure would leave a big hole in his daily adventures. He might try to convince her to come back immediately.
Natsu would probably be really excited at first. He'd be all over the place, asking a million questions and making sure Lucy is okay. Happy would be right there with him, trying to help in his own little Exceed way. Erza would be very protective. She'd make sure Lucy follows all the proper precautions and would offer to train her gently so she doesn't lose her fighting edge during pregnancy. Gray might be a bit awkward at first but would soon warm up and offer his support, like helping with any heavy lifting around Lucy's place.
One possible reason could be a misunderstanding. Maybe someone framed Lucy for something she didn't do, like stealing a powerful magic item from the guild. Another reason might be that she accidentally broke a very important and unbreakable guild rule without realizing it. For example, if there was a rule about not using a certain type of dark magic, and she unknowingly used it to save a friend.
The guild as a whole would likely mobilize. Erza would start formulating a strategic plan. She'd consider the strengths and weaknesses of Acnologia and figure out the best way to approach the situation. Gray would also be ready to fight, using his ice - make magic to support the rescue mission. They would all be united in their determination to get Lucy back safely.
He might be really angry at first. Natsu is a passionate character, and being kicked out unjustly would make him furious. He could storm off vowing to prove his worth and show the guild they made a mistake.
Lucy could be extremely excited. After all, finding Igneel is like stumbling upon a legend come to life. She would likely be in awe of his presence. She might immediately think about how this discovery could benefit her friends in the Fairy Tail guild. She could also be very respectful and try to approach Igneel in a friendly manner.
Their friends in Fairy Tail would likely be very excited. Erza, for example, would probably be super supportive and offer practical advice on things like baby - proofing a home. Natsu might be a bit clueless at first but would be really happy for them. Lucy would be thrilled and might start knitting baby clothes. Happy would be flying around them, chirping happily. Overall, their friends would form a great support system for Gray and Juvia during this time.
Their friends would likely be very excited. Lucy would probably be overjoyed and offer to help with things like baby clothes shopping. Gray might act a bit gruff on the outside but secretly be happy for them. Erza would be very protective, making sure that Lisanna has everything she needs and that the guild is a safe environment for the baby. Happy, Natsu's Exceed friend, would be constantly around, making cute comments about the baby and offering his own unique brand of support.
Natsu might be really confused and sad at first. He's used to having Lucy around for adventures. But he would probably respect her decision in the end, knowing it's for the baby.
The other members of Fairy Tail would likely be very excited. Natsu might be a bit clueless at first but would soon be happy for them. Lucy would probably be super excited and offer to help Levy with anything she needs. Erza would be more reserved in her excitement but would offer her protection. Gray would probably make some teasing remarks to Gajeel about becoming a father.