No, it means it would be superscript in a professionally written document, just as B and I still exist for the reason of something being bold or italic when professionally written, as opposed to EM and STRONG which have the semantic meaning of "emphasis" and "More emphasis" respectively. EM and STRONG are not, nor ever were replacements for B and I as they mean something entirely different.
Just because a tag means it would be that in professional writing, it does not mean that said appearance is it's meaning -- that's one of the biggest hurdles to semantic markup the "visually oriented" have trouble getting past. When TBL made HTML not all devices could even show bold.. or italic... or different size fonts... which if he was making it for cross-platform compatibility of documents, why would he include tags that 'mean' that? He didn't. They mean the text would be that in a professionally written document, not that they must be shown as that or mean the default presentation.
Case in point, THIS example (a friend came up with years ago) shows all four of those tags being used properly:
<i>GURPS,</i> <b>Steve Jackson Games'</b> flagship role-playing game, was first released in 1985. Several licensed adaptations of other companies' games exist for the system, such as <i>GURPS Bunnies and Burrows.</i> However, <b>SJ Games</b> has no connection with <b>Wizards of the Coast</b>, producers of the <i>Dungeons and Dragons</i> RPG. <em>No <i>GURPS,</i> content is open-source.</em> <strong>Do not plagiarize <b>SJ Games</b> work!</strong>
That's a doozy, isn't it. Book titles are italic NOT because you are emphasizing them, but because in professional writing they would be italic. How we communicate that it's a book title visually is up to the user-agent or the stylesheet. Company names being a proper name are bolded because that's what they ARE, we're not adding "more emphasis" to them. A disclaimer message might be receiving emphasis, and a warning ending with an exclamation point sure as shine-ola gets "MORE emphasis". That's completely valid and proper semantic use of those tags... Anyone saying otherwise doesn't know enough about HTML to be saying so, and likely doesn't get why HTML even exists or what it's for!
Which is why the people who claim that B and I are 'deprecated' are full of manure, and why the people saying to use STRONG and EM instead of B and I don't understand the meaning of ANY of those tags. Does "CITE" also mean italic? It's default appearance is italic!
It's the same as how SMALL means de-emphasis, or how HR does NOT mean "draw a line across the screen", or how the various numbered headings do NOT mean "make the text bigger". Semantic markup -- though I'm tempted to stop using that euphemism and start calling it what it <em>REALLY IS</em>: <strong>Using <acronym title="HyperText Markup Language">HTML</acronym> properly according to the specifications </strong>!
Again, if you are choosing tags based on their default appearance instead of their meaning and reason they exist, you're choosing the wrong tags for all the wrong reasons.
Which brings us to superscript, which:
Many scripts (e.g., French) require superscripts or subscripts for proper rendering. The SUB and SUP elements should be used to markup text in these cases.
E = mc<sup>2</sup>
<SPAN lang="fr">M<sup>lle</sup> Dupont</SPAN>
It implies a meaning, like in a mathematical formula or in specific languages... which is why it's the wrong tag if all you want to do is slide an element around for presentation -- as that would too be choosing the wrong tag for the wrong reason; since presentation has no business in the markup, that's either to be determined by the UA to the capabilities of the device, or by your stylesheets.
SUP means the text would be SuperScript for a reason, and the UA should attempt to convey that meaning, it does not -- like any of the other tags -- mean it's default presentation in visual user-agents of "slide the text up and make it smaller".
Why? Because there's more to HTML than what things happen to look like by default on the screen you happen to be sitting in front of.