This statement alone is sufficient to squash this rumour.
Volvo initially came up with a low floor double decker at the beginning, which is the B7TL, but the engine was deemed insufficient to power the type built to the HK-specification i.e. 12m air-conditioned. Instead of developing a brand new product line, the decision was to mate the B7L front to the Olympian's rear module, which becomes the Super Olympian (B10TL). To that end, the B10TL is indeed a stopgap because Volvo didn't really plan to keep the D10A engine going (which was to be replaced by the D7 and D12 engines) beyond Euro 2, but at the end they did of course.
These all happened in late 1990s and the B9TL did not even come into the equation until much later i.e. 2004/5. The B9TL is essentially a B7TL with the D9A/B engine, plus new front suspensions and it finally rationalise Volvo's 2 and 3-axle double decker product lines by replacing both the B7TL and B10TL.
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