The Master's Vault character options

Hi guys, I'm new to Roll20 and relatively new to D&D. Sorry in advance if this question has already been answered, I couldn't find it anywhere. I'm thinking about doing a newb run of The Master's Vault and I was wondering if the pregen characters are specific to the story or would it be ok to allow PC's to create their own?
I believe they are just there to ease new players in (so you can forgo the creation process if you want) its been a long time since I have read through it honestly tho, but as a big part of TTRPG's is having your own characters available for play most are written without assigning a direct need for specific characters to be involved.
I've run this module with two groups, and you can definitely use your own characters.  The pregens have Bonds which tie in very nicely to the story, which is helpful if you're running it as a one-shot, but you could just as easily do without them, or just have the players take those bonds for their own characters, if you really like them.
Thanks for the quick response! This is great information. I'm gonna give them the choice of pregen or custom, see how it goes. Thanks again!
I started running this at the end of March and have run it every 2 weeks.  The module plays very well so far with characters made by the players.  I have been using material from the 3.5 Basic Set as add on  to the module obviously converted to 5e and the players have liked it.  The master has not even died yet but is about to in the next game so we will see where they go with it but I am looking forward into getting them started and then interspersing more of the Basic material to continue their starting adventures.