Possible bad news for Canon: Sony plans to acquire Tamron?

Japanese business magazine Diamond reports that Sony Group has proposed acquiring lens manufacturer Tamron. The potential deal is said to be worth approximately 200 billion yen.
I cannot access the complete Diamond article, so some details and context may be missing. However, if the report is accurate, the timing could be particularly significant for Canon users. Tamron has only recently begun producing autofocus lenses for Canon’s RF mount, starting with APS-C models for EOS R cameras.

Why would Sony want to acquire Tamron?
Sony has maintained a stake of roughly 15% in Tamron for many years. At the same time, activist investment firms—including Effissimo Capital Management—have built substantial positions in the lens manufacturer.
Buying Tamron outright could help Sony limit external influence over an important business partner. It would also give the company greater control over Tamron’s optical expertise, manufacturing resources, and future product strategy.
Tamron is already one of the most important third-party lens manufacturers for Sony E-mount, so the two companies have a well-established relationship.

What could the acquisition mean for Canon RF users?
Until recently, photographers using Canon mirrorless cameras had very limited access to third-party autofocus lenses. The arrival of Tamron’s first APS-C RF-mount lenses therefore represented an important step toward a broader and more competitive lens ecosystem.
For EOS R7, R10, R50, and R100 owners, third-party APS-C lenses can fill obvious gaps in Canon’s RF-S lineup. Tamron is especially well positioned to provide compact zooms with useful focal ranges and competitive prices.
A Sony takeover could now raise questions about how far Tamron’s support for Canon RF will expand.

Possible consequences for the Canon RF system

• RF development could continue normally: Tamron may be allowed to remain operationally independent. If its Canon lenses are commercially successful, there would be a clear financial reason to continue producing them.
• New RF lenses could receive a lower priority: Under Sony ownership, Tamron might devote more development and manufacturing resources to E-mount products.
• Full-frame RF lenses could be delayed: Canon users are still waiting to see whether Tamron’s APS-C support will eventually lead to full-frame RF products. A change in ownership could influence that decision.
• Canon’s licensing strategy could become more complicated: Tamron’s RF products presumably depend on an agreement with Canon. Canon may be less enthusiastic about sharing technical access with a lens company controlled by one of its main camera competitors.
• The RF-S lineup could lose momentum: Tamron had only just begun contributing to Canon’s APS-C mirrorless system. Any slowdown would be disappointing for users hoping to see more affordable alternatives to Canon lenses.

Canon may have more to lose than Sony
Sony already benefits from one of the largest collections of native mirrorless lenses on the market. Canon, by comparison, has only recently started opening the RF mount to selected third-party autofocus products.
That makes Tamron’s entry especially important. The company could help strengthen the RF-S system with lenses that Canon may not prioritize itself. If Sony ownership limits Tamron’s RF ambitions, Canon users could lose a promising source of new lenses just as the lineup was beginning to expand.
There is no reason to assume that Tamron would immediately stop making Canon lenses. Existing agreements could remain in place, and continuing to serve RF users might be commercially attractive. Nevertheless, Sony ownership would introduce a new strategic complication that did not previously exist.
Diamond is considered a credible source of Japanese financial reporting, but it remains unclear whether the proposed acquisition will lead to a completed transaction. From Canon’s perspective, the most important question is whether Tamron’s recent move into APS-C RF lenses will continue—or whether the expansion will end before it really gets started.
Would a Sony-owned Tamron continue developing RF and RF-S lenses, or would Canon users once again be left with fewer third-party choices? What do you think?