Depends on your definition of "upgrade". To me, there are three paths you can take when you're starting out on purchasing your first lenses. But there is a "chicken-and-the-egg" problem, here. To know what lens you want, you have to have experience with a variety of lenses.
Shotgun coverage with "training wheels" lenses
The 18-55/55-250 IS "twin kit" generally will give you better optical quality at a lower price. But you do have the 55mm "breakover" point, and the fact that neither of these lenses would be considered best-in-class. I'd also toss on the EF 50/1.8 II (or EF 40mm f/2.8 STM) as the third basic "training wheels" lens so you get a sense of wide vs. tele, fast vs. slow, IS vs. non-IS, and zoom vs. prime for less cost than one good midgrade lens. This way, you'll get a better idea of why you'd want to move to a different lens and what features you'll want (aside, possibly, from the benefits of USM, since none of these lenses have it).
The downside is that these "training wheels" lenses are likely to be replaced when more funds and experience lead you to wanting different lenses, whether that be shooting full frame, shooting silently, autofocusing more quickly, more reach, better contrast, better low-light performance, etc. And these "training wheel" lenses won't retain a ton of value for resale.
Just Get a Superzoom
An 18-200mm superzoom does have more optical quality compromises--particularly with the wide end of the lens exhibiting wave distortion, but this is par for the course of any superzoom, and for the focal length range it covers, the performance is better than expected. And even if you do upgrade to better lenses in the future, you may still want to keep a superzoom around for that focal length range convenience. When traveling, if you need an all-in-one solution enough to compromise on image quality, this lens may still earn a place in your permanent lineup.
Spend Big Up Front
You can, of course, also skip "training wheels" lenses altogether and jump straight to getting the final "pro" lens of your dreams if you have the money and on-hand expertise to do so. But if you rely on an advisor, be certain they're going to tell you what you need vs. what they like. :) You may also want to find a good rental place so you can try before you buy. Obviously, without the experience to judge for yourself, the downside is that you can spend a lot of money only to find that the lens is not the best fit for you and what/how you want to shoot. But at least most expensive lenses retain value well upon resale.
It's up to you which approach is the one most likely to make you happy.