The '140 years of top flight rugby'/'never outside the top flight' comment is an interesting one, and needs a bit of correction and clarification.
Firstly, we should be clear that the club has not had '140 years of top flight rugby' - mainly because, in the context in which this comment is meant, that is impossible. When the club was formed in 1876 there were no competitive league (or cup) fixtures. The club played local (minor) clubs in self-arranged friendlies for the first few seasons, and gradually over the next decade or so the standing of these opponents rose, as the prominence of Warrington did too.
The Lancashire RFU was slow in starting competitive games, so the sub-union in West Lancashire took up the task. A cup comp was first (as was the case in most forms of football at the time), and it wasn't until 1889 that a league (the West Lancashire League) was started. Whilst very localised I would argue this was a 'top flight' competition, including as it did not only the best teams in the area, but clubs that would continue to be prominent through the evolving competitions that followed, such as Wigan, Saints & Widnes.
However, for the next 2 seasons, Warrington elected not to compete in this league - so they actually gave up their top flight status almost at the first opportunity!! They did re-join league football in 1892 when the county-wide Lancashire First Class Competition was started. The club then obviously joined the Northern Union in 1895, were in the group of teams that split to form the Northern Rugby Football League in 1901, and played in the first division through the periods when two or more divisions were in situ in the three eras this has been seen (1902-5, 1962-4, 1973 onwards).
An important point to note though is that the club did not play in the war-time league from 1940 for a period of 4 years, after Wilderspool was requisitioned for the war effort.
All this makes the claim slightly tenuous - as a result of the spell out during the war, there are a few teams (I can't remember off the top of my head exactly, but IIRC Wigan & Leeds) who have played more seasons in the top division than us. Both have of course played outside the top flight - Wigan once in the post-1973 era, and Leeds way back at the start of the last century.
As for the middle 8s standing, it's an interesting one viewed from a historical & statistical context. It's viewed as a seperate competition statistically, as tries count towards a player's record, but do not count as 'Super League' tries, unlike those scored in the Super 8s. It's most akin to an elongated relegation play-off, as used to be played pre first world war, when the bottom club of one division would play the top club of another forthe higher status.
Given all this, there's an argument both ways, as has been made above. Interesting, the split is quite familiar, with the typically 'glass half full' folk arguing we lose our record, and the optimists saying it doesn't matter!
FWIW, I don't judge it affects our slightly spurious claim either, as you can just continue to twist it to make it even more tenuous, but still hold. So if you changed the wording to be that 'we have never started a season outside the top flight', or that 'every season we have played competitive football we have competed in the top flight', both statements are factually correct.
That said, whilst it's an interesting debate, I think we're missing all missing the point: it's not going to happen anyway