Do u think its wrong that my father left my step mother everything and us nothing in the WILL?

have a step mother me along with 3 other siblings, we are older now 29, 26,26, & 24 years old, im the eldest, I just found out that when my father pes it all goes to our step mother and her new children with my dad. Me and my husband has been working for his business, he always lead us to beleive that we were gonna take over one day and own it, and he even flat out told us that too at one point. Now he is saying that its all going to my step mom. Is this wrong that my father isnt going to leave his 4 other children anything, i mean after he pes my step mother will not have anything to do with us, she already pretty much doesnt even want to claim us as hers anyways. Is this wrong & betrayal and should i talk with my father about this?