Probably not. But it depends on the doctor concerned. They are all so different, some will say, ‘I don’t think it’s MS’, when they know it’s at least a CIS and possibly MS. Others will hedge their bets. It would be unusual for a doctor to say it’s most likely MS, unless they thought it was. They can tell an awful lot from a physical exam, some reflex results are quite typical for MS and others for different problems. He’ll also have seen the MRI and maybe only been waiting for LP results (or vice versa).
But don’t count your chickens until the consultant actually says the words.
In the meantime, do your own research about MS, use the tag at the top of this page for the MSS info: About MS. And maybe have a look at https://www.mstrust.org.uk/about-ms/ms-treatments/ms-decisions-aid So that if he does say it is MS, you’ve got an idea about the various disease modifying drugs available.
Don’t get too disheartened if you get to the appointment and you don’t get a diagnosis, or not the one you’re expecting. If you have someone who can come with you to the appointment it’s a good idea, apart from anything, they can help you remember everything that’s said. There’s a little known ailment called ‘neurologitis’, basically it’s where you’re sitting in the room with the consultant thinking you understand every word and that you’ll remember what’s said. You then walk out of the room and say ‘what the hell did he say?’ And ‘what did he mean by X?’ Or ‘what did blah mean?’
Meanwhile feel free to keep asking questions on here, or even just to get a bit of moral support.