Last ten years 6.5 calibers I’ve rebarrelled or made as full custom
30% creed needy
10% 260 Rem
50% 6.5 x 47
20% 6.5 x 55
Oh and One 6.5 PRC and two 260 Improved
Interesting! But, of course one thing to remember - the overwhelming 'winner' in this list, 6.5X47L, is virtually unavailable as a factory chambering and was only barely so in its heyday some years back, so you go to a gunsmith if you want one. Creedmoor, 260, and 6.5X55, even PRC will see several factory product sales elsewhere for every gunsmith production. That is also of course if you can find anybody actually putting 260 Rem or 6.5X55 examples out of the factory gate (as opposed to listing them). Which brings us back to the OP and the reason for this topic.
Remington shamefully failed to support its 260 even in the days when it was being widely used and gaining huge publicity in US tactical and sniper disciplines. AFAIK, Remington never produced a single match bullet version of the cartridge and seems content to let it drift on as a second if not third tier deer cartridge. The company's motto seems to be that if an introduction doesn't prove a huge success within 18 months, then forget it and try something else.
The 6.5X47L is a lovely little cartridge, but was never going to be a commercial success. No major US manufacturer was going to adopt it, if nothing else because it wasn't invented in the USA, and it moreover it represented a downsizing when the entire market trend in the US was in the opposite direction to larger and larger cartridges with ever higher MVs / MEs.
6.5X55mm was never going to be more than a niche market number in the world's (far!) largest market, the USA. Funny foreign design; long action (unacceptable to many Americans who've grown up with received wisdom that everything can and should be crammed into short action designs - cf 300WSM; 338 Federal and lots more); low-pressure / low performance US produced factory ammo (SAAMI MAP 46,000 C.U.P. and most US offerings actually well below that). As soon as the Creedmoor appeared, US designed and made, same or higher performance, cheaper factory ammo and short action, 98 out of 100 Americans stopped even considering the old Scandi design.
The interesting question to me re the absence of actual 6.5X55s being turned out by their traditional makers is
WHY? and the key subsidiary question there is: Have new European buyers / users entering stalking / shooting stopped considering the cartridge preferring the Creedmoor and others, or is it just that more business and higher turnover can be generated in the short term by prioritising and tailoring production decisions to meet the demand of the currently overheated US firearms market? If the former, 6.5X55 is on the slippery slope although European factory ammo will continue to be made for decades to supply existing rifles. If the latter, SAKO and Tikka can just as quickly switch back to producing 6.5X55s if and when US demand declines.