Is there a name for the phenomenon of activists using seemingly unrelated global events to further their cause?
I think "crisis exploitation" may be appropriate as a general term for demands for change for both direct and indirect relationships to the crisis in question.
Though, I suggest "crisis inflation" for the indirect relationship "caused by the crisis in question", and "crisis conflation" for the indirect relationship "caused the crisis in question".
In Crisis Exploitation: Political and Policy Impacts of Framing Contests (PDF available for download),
When societies are confronted with major, disruptive emergencies, the fate of politicians and public policies hangs in the balance. Both government actors and their critics will try to escape blame for their occurrence, consolidate/strengthen their political capital, and advance/defend the policies they stand for. Crises thus generate framing contests to interpret events, their causes and the responsibilities and lessons involved in ways that suit their political purposes and visions of future policy directions.
This article attempts to formulate a theory of crisis exploitation, which we define as the purposeful utilisation of crisis-type rhetoric to significantly alter levels of political support for incumbent public office-holders and existing public policies and their alternatives. (Page 5}
The authors go on to explain different response to crises.
To a considerable extent, emergencies, disturbances and other forms of social crisis are all in the eye of the beholder. Following the classic Thomas theorem (“if men define their situations as real, they are real in their consequences”), it is not the events on the ground, but their public perception and interpretation that determine their potential impact on political office-holders and public policy. Accordingly, we define crises as events or developments widely perceived by members of relevant communities to constitute urgent threats to core community values and structures. (p. 6)
[...] We distinguish here between:
denial that the events in question represent more than an unfortunate incident, and thus a predisposition to downplay the idea that they should have any political or policy repercussions whatsoever.
deeming the events to be a critical threat to the collective good embodied in the status quo that existed before these events came to light, and thus a predisposition to defend the agents (incumbent office-holders) and tools (existing policies and organizational practices) of that status quo against criticism.
deeming the events to be a critical opportunity to expose deficiencies in the status quo ex ante, and hence a predisposition to pinpoint blameworthy behavior by status quo agents and dysfunctional policies and organizations, in order to mobilize support for their removal or substantive alteration. (pp. 6-7)
It is in this type-3 framing of the response to the crisis, that one may find both direct and indirect demands to address the changes wanted by political or governmental policy stakeholders.
Clearly, proponents of type 1 frames argue to minimize event significance, proponents of type 2 frames are more likely to acknowledge event significance, and proponents of type 3 frames are most likely to maximize event significance. The political risk of adhering to a type 1 frame is to be accused of ‘blindness’, ‘passivity’ and ‘rigidity’; the political risk of type 3 frames is to come across as ‘alarmist’ or ‘opportunistic’. Both can be accused of being divorced from reality, if not of outright lying. (p. 9)
It is in this sense of "maximiz[ing] event significance" that "crisis inflation", as a term, gains credence; in that, various political or governmental policy stakeholders may use the crisis as an opportunity to demand changes beyond that needed for the crisis in question.
“Never waste the opportunity offered by a good crisis,” is a quote first attributed to the Italian Renaissance writer Niccolo Machiavelli and repeated by politicians the world over ever since. Bloomberg
Regardless of the cause or response to any crisis, it makes Machiavellian political sense to "inflate" or "conflate" — to do whatever — to accomplish one's political ends.